Digital camera having printhead and ink supply

ABSTRACT

A digital camera is provided having a printhead for printing images digitally captured by the camera, an ink supply for supplying ink to the printhead, and a casing surrounding and encasing the printhead and ink supply so that the ink supply is unable to be accessed without destruction of the casing.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No. 11/102,845 filed on Apr. 11, 2005, which is a continuation of U.S. application Ser. No. 09/662,668 filed Sep. 15, 2000, now issued as U.S. Pat. No. 7,006,143, which is a divisional of U.S. application Ser. No. 09/113,086 filed Jul. 10, 1998, the entire contents of which are herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates substantially to the concept of a disposable camera having instant printing capabilities and in particular, discloses a method integrating the electronic components of a camera system.

BACKGROUND OF THE INVENTION

Recently, the concept of a “single use” disposable camera has become an increasingly popular consumer item. Disposable camera systems presently on the market normally include an internal film roll and a simplified gearing mechanism for traversing the film roll across an imaging system including a shutter and lensing system. The user, after utilizing a single film roll returns the camera system to a film development center for processing. The film roll is taken out of the camera system and processed and the prints returned to the user. The camera system is then able to be re-manufactured through the insertion of a new film roll into the camera system, the replacement of any worn or wearable parts and the re-packaging of the camera system in accordance with requirements. In this way, the concept of a single use “disposable” camera is provided to the consumer.

Recently, a camera system has been proposed by the present applicant which provides for a handheld camera device having an internal print head, image sensor and processing means such that images sense by the image sensing means, are processed by the processing means and adapted to be instantly printed out by the printing means on demand. The proposed camera system further discloses a system of internal “print rolls” carrying print media such as film on to which images are to be printed in addition to ink for supplying to the printing means for the printing process. The print roll is further disclosed to be detachable and replaceable within the camera system.

Unfortunately, such a system is likely to only be constructed at a substantial cost and it would be desirable to provide for a more inexpensive form of instant camera system which maintains a substantial number of the quality aspects of the aforementioned arrangement.

It would be further advantageous to provide for the effective interconnection of the sub components of a camera system.

SUMMARY OF THE INVENTION

According to the invention there is provided a recyclable, one-time use, print on demand, digital camera comprising:

a chassis carrying: —

-   -   an image sensor device for sensing an image;     -   a processing means for processing said sensed image;     -   a pagewidth print head for printing said sensed image;     -   an ink supply means for supplying ink to the print head;     -   a supply of print media on to which said sensed image is         printed; and

a casing surrounding and encasing said chassis so that the supply of print media is unable to be accessed without destruction of the casing.

The casing may comprise two shells, the shells being bonded together during one of a manufacturing process and a recycling process. In addition to the shells being bonded together, they may also be clipped together.

The shells of the casing may be of a synthetic plastics material so that the casing is recyclable.

The supply of print media may be carried via a holder on the chassis and the holder may be releasably supported on the chassis to facilitate its removal from the chassis to be replaced by a new supply of print media upon recycling of the camera.

The ink supply means may be refilled and a power supply means of the camera may be replaced at the same time as the supply of print media is replaced during said recycling of the camera.

The power supply means may be accommodated within the supply of print media.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 illustrates a front perspective view of the assembled camera of the preferred embodiment;

FIG. 2 illustrates a rear perspective view, partly exploded, of the preferred embodiment;

FIG. 3 is a perspective view of the chassis of the preferred embodiment;

FIG. 4 is a perspective view of the chassis illustrating mounting of electric motors;

FIG. 5 is an exploded perspective view of the ink supply mechanism of the preferred embodiment;

FIG. 6 is a rear perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;

FIG. 7 is a front perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;

FIG. 8 is an exploded perspective view of the platten unit of the preferred embodiment;

FIG. 9 is a perspective view of the assembled form of the platten unit;

FIG. 10 is also a perspective view of the assembled form of the platten unit;

FIG. 11 is an exploded perspective view of the printhead recapping mechanism of the preferred embodiment;

FIG. 12 is a close up, exploded perspective view of the recapping mechanism of the preferred embodiment;

FIG. 13 is an exploded perspective view of the ink supply cartridge of the preferred embodiment;

FIG. 14 is a close up, perspective view, partly in section, of the internal portions of the ink supply cartridge in an assembled form;

FIG. 15 is a schematic block diagram of one form of chip layer of the image capture and processing chip of the preferred embodiment;

FIG. 16 is an exploded perspective view illustrating the assembly process of the preferred embodiment;

FIG. 17 illustrates a front exploded perspective view of the assembly process of the preferred embodiment;

FIG. 18 illustrates a perspective view of the assembly process of the preferred embodiment;

FIG. 19 illustrates a perspective view of the assembly process of the preferred embodiment;

FIG. 20 is a perspective view illustrating the insertion of the platten unit in the preferred embodiment;

FIG. 21 illustrates the interconnection of the electrical components of the preferred embodiment;

FIG. 22 illustrates the process of assembling the preferred embodiment; and

FIG. 23 is a perspective view further illustrating the assembly process of the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

Turning initially simultaneously to FIG. 1 and FIG. 2 there are illustrated perspective views of an assembled camera constructed in accordance with the preferred embodiment with FIG. 1 showing a front perspective view and FIG. 2 showing a rear perspective view. The camera 1 includes a paper or plastic film jacket 2 which can include simplified instructions 3 for the operation of the camera system 1. The camera system 1 includes a first “take” button 4 which is depressed to capture an image. The captured image is output via output slot 6. A further copy of the image can be obtained through depressing a second “printer copy” button 7 whilst an LED light 5 is illuminated. The camera system also provides the usual viewfinder 8 in addition to a CCD image capture/lensing system 9.

The camera system 1 provides for a standard number of output prints after which the camera system 1 ceases to function. A prints left indicator slot 10 is provided to indicate the number of remaining prints. A refund scheme at the point of purchase is assumed to be operational for the return of used camera systems for recycling.

Turning now to FIG. 3, the assembly of the camera system is based around an internal chassis 12 which can be a plastic injection molded part. A pair of paper pinch rollers 28, 29 utilized for de-curling are snap fitted into corresponding frame holes eg. 26, 27.

As shown in FIG. 4, the chassis 12 includes a series of mutually opposed prongs e.g. 13, 14 into which is snapped fitted a series of electric motors 16, 17. The electric motors 16, 17 can be entirely standard with the motor 16 being of a stepper motor type. The motors 16,17 include cogs 19, 20 for driving a series of gear wheels. A first set of gear wheels is provided for controlling a paper cutter mechanism and a second set is provided for controlling print roll movement.

Turning next to FIGS. 5 to 7, there is illustrated an ink supply mechanism 40 utilized in the camera system. FIG. 5 illustrates a rear exploded perspective view, FIG. 6 illustrates a rear assembled perspective view and FIG. 7 illustrates a front assembled view. The ink supply mechanism 40 is based around an ink supply cartridge 42 which contains printer ink and a print head mechanism for printing out pictures on demand. The ink supply cartridge 42 includes a side aluminum strip 43 which is provided as a shear strip to assist in cutting images from a paper roll.

A dial mechanism 44 is provided for indicating the number of “prints left”. The dial mechanism 44 is snap fitted through a corresponding mating portion 46 so as to be freely rotatable.

As shown in FIG. 6, the mechanism 40 includes a flexible PCB strip 47 which interconnects with the print head and provides for control of the print head. The interconnection between the Flex PCB strip and an image sensor and print head chip can be via Tape Automated Bonding (TAB) strips 51, 58. A molded aspherical lens and aperture shim 50 (FIG. 5) is also provided for imaging an image onto the surface of the image sensor chip normally located within cavity 53 and a light box module or hood 52 is provided for snap fitting over the cavity 53 so as to provide for proper light control. A series of decoupling capacitors e.g. 34 can also be provided. Further a plug 45 (FIG. 7) is provided for re-plugging ink holes after refilling. A series of guide prongs e.g. 55-57 are further provided for guiding the flexible PCB strip 47.

The ink supply mechanism 40 interacts with a platten unit 60 which guides print media under a printhead located in the ink supply mechanism. FIG. 8 shows an exploded view of the platten unit 60, while FIGS. 9 and 10 show assembled views of the platten unit. The platten unit 60 includes a first pinch roller 61 which is snap fitted to one side of a platten base 62. Attached to a second side of the platten base 62 is a cutting mechanism 63 which traverses the platen unit 60 by means of a rod 64 having a screw thread which is rotated by means of cogged wheel 65 which is also fitted to the platten base 62. The screw threaded rod 64 mounts a block 67 which includes a cutting wheel 68 fastened via a fastener 69. Also mounted to the block 67 is a counter actuator which includes a pawl. The pawl 71 acts to rotate the dial mechanism 44 of FIG. 6 upon the return traversal of the cutting wheel. As shown previously in FIG. 6, the dial mechanism 44 includes a cogged surface which interacts with pawl 71 thereby maintaining a count of the number of photographs by means of numbers embossed on the surface of dial mechanism 44. The cutting mechanism 63 is inserted into the platten base 62 by means of a snap fit via clips e.g. 74.

The platen unit 60 includes an internal recapping mechanism 80 for recapping the printhead when not in use. The recapping mechanism 80 includes a sponge portion 81 and is operated via a solenoid coil so as to provide for recapping of the print head. In the preferred embodiment, there is provided an inexpensive form of printhead re-capping mechanism provided for incorporation into a handheld camera system so as to provide for printhead re-capping of an inkjet printhead.

FIG. 11 illustrates an exploded view of the recapping mechanism whilst FIG. 12 illustrates a close up of the end portion thereof. The re-capping mechanism 80 is structured around a solenoid including a 16 turn coil 75 which can comprise insulated wire. The coil 75 is turned around a first stationery solenoid arm 76 which is mounted on a bottom surface of the platen base 62 (FIG. 8) and includes a post portion 77 to magnify effectiveness of operation. The arm 76 can comprise a ferrous material.

A second moveable arm 78 of the solenoid actuator is also provided. The arm 78 is moveable and is also made of ferrous material. Mounted on the arm is a sponge portion surrounded by an elastomer strip 79. The elastomer strip 79 is of a generally arcuate cross-section and acts as a leaf spring against the surface of the printhead ink supply cartridge 42 (FIG. 5) so as to provide for a seal against the surface of the printhead ink supply cartridge 42. In the quiescent position an elastomer spring unit 87, 88 acts to resiliently deform the elastomer seal 79 against the surface of the ink supply unit 42.

When it is desired to operate the printhead unit, upon the insertion of paper, the solenoid coil 75 is activated so as to cause the arm 78 to move down to be adjacent to the end plate 76. The arm 78 is held against end plate 76 while the printhead is printing by means of a small “keeper current” in coil 75. Simulation results indicate that the keeper current can be significantly less than the actuation current. Subsequently, after photo printing, the paper is guillotined by the cutting mechanism 63 of FIG. 8 acting against aluminum strip 43, and rewound so as to clear the area of the re-capping mechanism 80. Subsequently, the current is turned off and springs 87, 88 return the arm 78 so that the elastomer seal is again resting against the printhead ink supply cartridge.

It can be seen that the preferred embodiment provides for a simple and inexpensive means of re-capping a printhead through the utilization of a solenoid type device having a long rectangular form. Further, the preferred embodiment utilizes minimal power in that currents are only required whilst the device is operational and additionally, only a low keeper current is required whilst the printhead is printing.

Turning next to FIGS. 13 and 14, FIG. 13 illustrates an exploded perspective of the ink supply cartridge 42 whilst FIG. 14 illustrates a close up sectional view of a bottom of the ink supply cartridge with the printhead unit in place. The ink supply cartridge 42 is based around a pagewidth printhead 102 which comprises a long slither of silicon having a series of holes etched on the back surface for the supply of ink to a front surface of the silicon wafer for subsequent ejection via a micro electromechanical system. The form of ejection can be many different forms such as those set out in the tables below.

Of course, many other inkjet technologies, as referred to the attached tables below, can also be utilized when constructing a printhead unit 102. The fundamental requirement of the ink supply cartridge 42 is the supply of ink to a series of color channels etched through the back surface of the printhead 102. In the description of the preferred embodiment, it is assumed that a three color printing process is to be utilized so as to provide full color picture output. Hence, the print supply unit includes three ink supply reservoirs being a cyan reservoir 104, a magenta reservoir 105 and a yellow reservoir 106. Each of these reservoirs is required to store ink and includes a corresponding sponge type material 107-109 which assists in stabilizing ink within the corresponding ink channel and inhibiting the ink from sloshing back and forth when the printhead is utilized in a handheld camera system. The reservoirs 104, 105, 106 are formed through the mating of first exterior plastic piece 110 and a second base piece 111.

At a first end 118 of the base piece 111 a series of air inlet 113-115 are provided. Each air inlet leads to a corresponding winding channel which is hydrophobically treated so as to act as an ink repellent and therefore repel any ink that may flow along the air inlet channel. The air inlet channel further takes a convoluted path assisting in resisting any ink flow out of the chambers 104-106. An adhesive tape portion 117 is provided for sealing the channels within end portion 118.

At the top end, there is included a series of refill holes (not shown) for refilling corresponding ink supply chambers 104, 105, 106. A plug 121 is provided for sealing the refill holes.

Turning now to FIG. 14, there is illustrated a close up perspective view, partly in section through the ink supply cartridge 42 of FIG. 13 when formed as a unit. The ink supply cartridge includes the three color ink reservoirs 104, 105, 106 which supply ink to different portions of the back surface of printhead 102 which includes a series of apertures 128 defined therein for carriage of the ink to the front surface.

The ink supply cartridge 42 includes two guide walls 124, 125 which separate the various ink chambers and are tapered into an end portion abutting the surface of the printhead 102. The guide walls 124, 125 are further mechanically supported by block portions e.g. 126 which are placed at regular intervals along the length of the ink supply unit. The block portions 126 have space at portions close to the back of printhead 102 for the flow of ink around the back surface thereof.

The ink supply unit is preferably formed from a multi-part plastic injection mold and the mold pieces e.g. 110, 111 (FIG. 13) snap together around the sponge pieces 107, 109. Subsequently, a syringe type device can be inserted in the ink refill holes and the ink reservoirs filled with ink with the air flowing out of the air outlets 113-115. Subsequently, the adhesive tape portion 117 and plug 121 are attached and the printhead tested for operation capabilities. Subsequently, the ink supply cartridge 42 can be readily removed for refilling by means of removing the ink supply cartridge, performing a washing cycle, and then utilizing the holes for the insertion of a refill syringe filled with ink for refilling the ink chamber before returning the ink supply cartridge 42 to a camera.

Turning now to FIG. 15, there is shown an example layout of the Image Capture and Processing Chip (ICP) 48.

The Image Capture and Processing Chip 48 provides most of the electronic functionality of the camera with the exception of the print head chip. The chip 48 is a highly integrated system. It combines CMOS image sensing, analog to digital conversion, digital image processing, DRAM storage, ROM, and miscellaneous control functions in a single chip.

The chip is estimated to be around 32 mm² using a leading edge 0.18 micron CMOS/DRAM/APS process. The chip size and cost can scale somewhat with Moore's law, but is dominated by a CMOS active pixel sensor array 201, so scaling is limited as the sensor pixels approach the diffraction limit.

The ICP 48 includes CMOS logic, a CMOS image sensor, DRAM, and analog circuitry. A very small amount of flash memory or other non-volatile memory is also preferably included for protection against reverse engineering.

Alternatively, the ICP can readily be divided into two chips: one for the CMOS imaging array, and the other for the remaining circuitry. The cost of this two chip solution should not be significantly different than the single chip ICP, as the extra cost of packaging and bond-pad area is somewhat cancelled by the reduced total wafer area requiring the color filter fabrication steps.

The ICP preferably contains the following functions:

Function 1.5 megapixel image sensor Analog Signal Processors Image sensor column decoders Image sensor row decoders Analogue to Digital Conversion (ADC) Column ADC's Auto exposure 12 Mbits of DRAM DRAM Address Generator Color interpolator Convolver Color ALU Halftone matrix ROM Digital halftoning Print head interface 8 bit CPU core Program ROM Flash memory Scratchpad SRAM Parallel interface (8 bit) Motor drive transistors (5) Clock PLL JTAG test interface Test circuits Busses Bond pads

The CPU, DRAM, Image sensor, ROM, Flash memory, Parallel interface, JTAG interface and ADC can be vendor supplied cores. The ICP is intended to run on 1.5V to minimize power consumption and allow convenient operation from two AA type battery cells.

FIG. 15 illustrates a layout of the ICP 48. The ICP 48 is dominated by the imaging array 201, which consumes around 80% of the chip area. The imaging array is a CMOS 4 transistor active pixel design with a resolution of 1,500×1,000. The array can be divided into the conventional configuration, with two green pixels, one red pixel, and one blue pixel in each pixel group. There are 750×500 pixel groups in the imaging array.

The latest advances in the field of image sensing and CMOS image sensing in particular can be found in the October, 1997 issue of IEEE Transactions on Electron Devices and, in particular, pages 1689 to 1968. Further, a specific implementation similar to that disclosed in the present application is disclosed in Wong et al., “CMOS Active Pixel Image Sensors Fabricated Using a 1.8V, 0.25 μm CMOS Technology”, IEDM 1996, page 915

The imaging array uses a 4 transistor active pixel design of a standard configuration. To minimize chip area and therefore cost, the image sensor pixels should be as small as feasible with the technology available. With a four transistor cell, the typical pixel size scales as 20 times the lithographic feature size. This allows a minimum pixel area of around 3.6 μm×3.6 μm. However, the photosite must be substantially above the diffraction limit of the lens. It is also advantageous to have a square photosite, to maximize the margin over the diffraction limit in both horizontal and vertical directions. In this case, the photosite can be specified as 2.5 μm×2.5 μm. The photosite can be a photogate, pinned photodiode, charge modulation device, or other sensor.

The four transistors are packed as an ‘L’ shape, rather than a rectangular region, to allow both the pixel and the photosite to be square. This reduces the transistor packing density slightly, increasing pixel size. However, the advantage in avoiding the diffraction limit is greater than the small decrease in packing density.

The transistors also have a gate length which is longer than the minimum for the process technology. These have been increased from a drawn length of 0.18 micron to a drawn length of 0.36 micron. This is to improve the transistor matching by making the variations in gate length represent a smaller proportion of the total gate length.

The extra gate length, and the ‘L’ shaped packing, mean that the transistors use more area than the minimum for the technology. Normally, around 8 μm² would be required for rectangular packing. Preferably, 9.75 μm² has been allowed for the transistors.

The total area for each pixel is 16 μm², resulting from a pixel size of 4 μm×4 μm. With a resolution of 1,500×1,000, the area of the imaging array 101 is 6,000 μm×4,000 μm, or 24 mm².

The presence of a color image sensor on the chip affects the process required in two major ways:

-   -   The CMOS fabrication process should be optimised to minimize         dark current

Color filters are required. These can be fabricated using dyed photosensitive polyimides, resulting in an added process complexity of three spin coatings, three photolithographic steps, three development steps, and three hardbakes.

There are 15,000 analog signal processors (ASPs) 205, one for each of the columns of the sensor. The ASPs amplify the signal, provide a dark current reference, sample and hold the signal, and suppress the fixed pattern noise (FPN).

There are 375 analog to digital converters 206, one for each four columns of the sensor array. These may be delta-sigma or successive approximation type ADC's. A row of low column ADC's are used to reduce the conversion speed required, and the amount of analog signal degradation incurred before the signal is converted to digital. This also eliminates the hot spot (affecting local dark current) and the substrate coupled noise that would occur if a single high speed ADC was used. Each ADC also has two four bit DAC's which trim the offset and scale of the ADC to further reduce FPN variations between columns. These DAC's are controlled by data stored in flash memory during chip testing.

The column select logic 204 is a 1:1500 decoder which enables the appropriate digital output of the ADCs onto the output bus. As each ADC is shared by four columns, the least significant two bits of the row select control 4 input analog multiplexors.

A row decoder 207 is a 1:1000 decoder which enables the appropriate row of the active pixel sensor array. This selects which of the 1000 rows of the imaging array is connected to analog signal processors. As the rows are always accessed in sequence, the row select logic can be implemented as a shift register.

An auto exposure system 208 adjusts the reference voltage of the ADC 205 in response to the maximum intensity sensed during the previous frame period. Data from the green pixels is passed through a digital peak detector. The peak value of the image frame period before capture (the reference frame) is provided to a digital to analogue converter (DAC), which generates the global reference voltage for the column ADCs. The peak detector is reset at the beginning of the reference frame. The minimum and maximum values of the three RGB color components are also collected for color correction.

The second largest section of the chip is consumed by a DRAM 210 used to hold the image. To store the 1,500×1,000 image from the sensor without compression, 1.5 Mbytes of DRAM 210 are required. This equals 12 Mbits, or slightly less than 5% of a 256 Mbit DRAM. The DRAM technology assumed is of the 256 Mbit generation implemented using 0.18 μm CMOS.

Using a standard 8F cell, the area taken by the memory array is 3.11 mm². When row decoders, column sensors, redundancy, and other factors are taken into account, the DRAM requires around 4 mm².

This DRAM 210 can be mostly eliminated if analog storage of the image signal can be accurately maintained in the CMOS imaging array for the two seconds required to print the photo. However, digital storage of the image is preferable as it is maintained without degradation, is insensitive to noise, and allows copies of the photo to be printed considerably later.

A DRAM address generator 211 provides the write and read addresses to the DRAM 210. Under normal operation, the write address is determined by the order of the data read from the CMOS image sensor 201. This will typically be a simple raster format. However, the data can be read from the sensor 201 in any order, if matching write addresses to the DRAM are generated. The read order from the DRAM 210 will normally simply match the requirements of a color interpolator and the print head. As the cyan, magenta, and yellow rows of the print head are necessarily offset by a few pixels to allow space for nozzle actuators, the colors are not read from the DRAM simultaneously. However, there is plenty of time to read all of the data from the DRAM many times during the printing process. This capability is used to eliminate the need for FIFOs in the print head interface, thereby saving chip area. All three RGB image components can be read from the DRAM each time color data is required. This allows a color space converter to provide a more sophisticated conversion than a simple linear RGB to CMY conversion.

Also, to allow two dimensional filtering of the image data without requiring line buffers, data is re-read from the DRAM array.

The address generator may also implement image effects in certain models of camera. For example, passport photos are generated by a manipulation of the read addresses to the DRAM. Also, image framing effects (where the central image is reduced), image warps, and kaleidoscopic effects can all be generated by manipulating the read addresses of the DRAM.

While the address generator 211 may be implemented with substantial complexity if effects are built into the standard chip, the chip area required for the address generator is small, as it consists only of address counters and a moderate amount of random logic.

A color interpolator 214 converts the interleaved pattern of red, 2× green, and blue pixels into RGB pixels. It consists of three 8 bit adders and associated registers. The divisions are by either 2 (for green) or 4 (for red and blue) so they can be implemented as fixed shifts in the output connections of the adders.

A convolver 215 is provided as a sharpening filter which applies a small convolution kernel (5×5) to the red, green, and blue planes of the image. The convolution kernel for the green plane is different from that of the red and blue planes, as green has twice as many samples. The sharpening filter has five functions:

-   -   to improve the color interpolation from the linear interpolation         provided by the color interpolator, to a close approximation of         a sinc interpolation;     -   to compensate for the image ‘softening’ which occurs during         digitisation;     -   to adjust the image sharpness to match average consumer         preferences, which are typically for the image to be slightly         sharper than reality. As the single use camera is intended as a         consumer product, and not a professional photographic products,         the processing can match the most popular settings, rather than         the most accurate;     -   to suppress the sharpening of high frequency (individual pixel)         noise. The function is similar to the ‘unsharp mask’ process;         and     -   to antialias Image Warping.

These functions are all combined into a single convolution matrix. As the pixel rate is low (less than 1 Mpixel per second) the total number of multiplies required for the three color channels is 56 million multiplies per second. This can be provided by a single multiplier. Fifty bytes of coefficient ROM are also required.

A color ALU 113 combines the functions of color compensation and color space conversion into the one matrix multiplication, which is applied to every pixel of the frame. As with sharpening, the color correction should match the most popular settings, rather than the most accurate.

A color compensation circuit of the color ALU provides compensation for the lighting of the photo. The vast majority of photographs are substantially improved by a simple color compensation, which independently normalizes the contrast and brightness of the three color components.

A color look-up table (CLUT) 212 is provided for each color component. These are three separate 256×8 SRAMs, requiring a total of 6,144 bits. The CLUTs are used as part of the color correction process. They are also used for color special effects, such as stochastically selected “wild color” effects.

A color space conversion system of the color ALU converts from the RGB color space of the image sensor to the CMY color space of the printer. The simplest conversion is a 1's complement of the RGB data. However, this simple conversion assumes perfect linearity of both color spaces, and perfect dye spectra for both the color filters of the image sensor, and the ink dyes. At the other extreme is a tri-linear interpolation of a sampled three dimensional arbitrary transform table. This can effectively match any non-linearity or differences in either color space. Such a system is usually necessary to obtain good color space conversion when the print engine is a color electrophotographic

However, since the non-linearity of a halftoned ink jet output is very small, a simpler system can be used. A simple matrix multiply can provide excellent results. This requires nine multiplies and six additions per contone pixel. However, since the contone pixel rate is low (less than 1 Mpixel/sec) these operations can share a single multiplier and adder. The multiplier and adder are used in a color ALU which is shared with the color compensation function.

Digital halftoning can be performed as a dispersed dot ordered dither using a stochastic optimized dither cell. A halftone matrix ROM 216 is provided for storing dither cell coefficients. A dither cell size of 32×32 is adequate to ensure that the cell repeat cycle is not visible. The three colors—cyan, magenta, and yellow—are all dithered using the same cell, to ensure maximum co-positioning of the ink dots. This minimizes ‘muddying’ of the mid-tones which results from bleed of dyes from one dot to adjacent dots while still wet. The total ROM size required is 1 KByte, as the one ROM is shared by the halftoning units for each of the three colors.

The digital halftoning used is dispersed dot ordered dither with stochastic optimized dither matrix. While dithering does not produce an image quite as ‘sharp’ as error diffusion, it does produce a more accurate image with fewer artifacts. The image sharpening produced by error diffusion is artificial, and less controllable and accurate than ‘unsharp mask’ filtering performed in the contone domain. The high print resolution (1,600 dpi×1,600 dpi) results in excellent quality when using a well formed stochastic dither matrix.

Digital halftoning is performed by a digital halftoning unit 217 using a simple comparison between the contone information from the DRAM 210 and the contents of the dither matrix 216. During the halftone process, the resolution of the image is changed from the 250 dpi of the captured contone image to the 1,600 dpi of the printed image. Each contone pixel is converted to an average of 40.96 halftone dots.

The ICP incorporates a 16 bit microcontroller CPU core 219 to run the miscellaneous camera functions, such as reading the buttons, controlling the motor and solenoids, setting up the hardware, and authenticating the refill station. The processing power required by the CPU is very modest, and a wide variety of processor cores can be used. As the entire CPU program is run from a small ROM 220 program compatibility between camera versions is not important, as no external programs are run. A 2 Mbit (256 Kbyte) program and data ROM 220 is included on chip. Most of this ROM space is allocated to data for outline graphics and fonts for specialty cameras. The program requirements are minor. The single most complex task is the encrypted authentication of the refill station. The ROM requires a single transistor per bit.

A Flash memory 221 may be used to store a 128 bit authentication code. This provides higher security than storage of the authentication code in ROM, as reverse engineering can be made essentially impossible. The Flash memory is completely covered by third level metal, making the data impossible to extract using scanning probe microscopes or electron beams. The authentication code is stored in the chip when manufactured. At least two other Flash bits are required for the authentication process: a bit which locks out reprogramming of the authentication code, and a bit which indicates that the camera has been refilled by an authenticated refill station. The flash memory can also be used to store FPN correction data for the imaging array. Additionally, a phase locked loop resealing parameter is stored for scaling the clocking cycle to an appropriate correct time. The clock frequency does not require crystal accuracy since no date functions are provided. To eliminate the cost of a crystal, an on chip oscillator with a phase locked loop 224 is used. As the frequency of an on-chip oscillator is highly variable from chip to chip, the frequency ratio of the oscillator to the PLL is digitally trimmed during initial testing. The value is stored in Flash memory 221. This allows the clock PLL to control the ink-jet heater pulse width with sufficient accuracy.

A scratchpad SRAM is a small static RAM 222 with a 6T cell. The scratchpad provided temporary memory for the 16 bit CPU. 1024 bytes is adequate.

A print head interface 223 formats the data correctly for the print head. The print head interface also provides all of the timing signals required by the print head. These timing signals may vary depending upon temperature, the number of dots printed simultaneously, the print medium in the print roll, and the dye density of the ink in the print roll.

The following is a table of external connections to the print head interface:

Connection Function Pins DataBits[0-7] Independent serial data to the eight segments 8 of the printhead BitClock Main data clock for the print head 1 ColorEnable[0-2] Independent enable signals for the CMY 3 actuators, allowing different pulse times for each color. BankEnable[0-1] Allows either simultaneous or interleaved 2 actuation of two banks of nozzles. This allows two different print speed/power consumption tradeoffs NozzleSelect[0-4] Selects one of 32 banks of nozzles for 5 simultaneous actuation ParallelXferClock Loads the parallel transfer register with the 1 data from the shift registers Total 20

The printhead utilized is composed of eight identical segments, each 1.25 cm long. There is no connection between the segments on the print head chip. Any connections required are made in the external TAB bonding film, which is double sided. The division into eight identical segments is to simplify lithography using wafer steppers. The segment width of 1.25 cm fits easily into a stepper field. As the printhead chip is long and narrow (10 cm×0.3 mm), the stepper field contains a single segment of 32 print head chips. The stepper field is therefore 1.25 cm×1.6 cm. An average of four complete print heads are patterned in each wafer step.

A single BitClock output line connects to all 8 segments on the printhead. The 8 DataBits lines lead one to each segment, and are clocked into the 8 segments on the print head simultaneously (on a BitClock pulse). For example, dot 0 is transferred to segment₀, dot 750 is transferred to segment₁, dot 1500 to segment₂ etc simultaneously.

The ParallelXferClock is connected to each of the 8 segments on the printhead, so that on a single pulse, all segments transfer their bits at the same time.

The NozzleSelect, BankEnable and ColorEnable lines are connected to each of the 8 segments, allowing the print head interface to independently control the duration of the cyan, magenta, and yellow nozzle energizing pulses. Registers in the Print Head Interface allow the accurate specification of the pulse duration between 0 and 6 ms, with a typical duration of 2 ms to 3 ms.

A parallel interface 125 connects the ICP to individual static electrical signals. The CPU is able to control each of these connections as memory mapped I/O via a low speed bus.

The following is a table of connections to the parallel interface:

Connection Direction Pins Paper transport stepper motor Output 4 Capping solenoid Output 1 Copy LED Output 1 Photo button Input 1 Copy button Input 1 Total 8

Seven high current drive transistors e.g. 227 are required. Four are for the four phases of the main stepper motor two are for the guillotine motor, and the remaining transistor is to drive the capping solenoid. These transistors are allocated 20,000 square microns (600,000 F) each. As the transistors are driving highly inductive loads, they must either be turned off slowly, or be provided with a high level of back EMF protection. If adequate back EMF protection cannot be provided using the chip process chosen, then external discrete transistors should be used. The transistors are never driven at the same time as the image sensor is used. This is to avoid voltage fluctuations and hot spots affecting the image quality. Further, the transistors are located as far away from the sensor as possible.

A standard JTAG (Joint Test Action Group) interface 228 is included in the ICP for testing purposes and for interrogation by the refill station. Due to the complexity of the chip, a variety of testing techniques are required, including BIST (Built In Self Test) and functional block isolation. An overhead of 10% in chip area is assumed for chip testing circuitry for the random logic portions. The overhead for the large arrays the image sensor and the DRAM is smaller.

The JTAG interface is also used for authentication of the refill station. This is included to ensure that the cameras are only refilled with quality paper and ink at a properly constructed refill station, thus preventing inferior quality refills from occurring. The camera must authenticate the refill station, rather than vice versa. The secure protocol is communicated to the refill station during the automated test procedure. Contact is made to four gold plated spots on the ICP/print head TAB by the refill station as the new ink is injected into the print head.

FIG. 16 illustrates a rear view of the next step in the construction process whilst FIG. 17 illustrates a front view.

Turning now to FIG. 16, the assembly of the camera system proceeds via first assembling the ink supply mechanism 40. The flex PCB is interconnected with batteries 84, only one of which is shown, which are inserted in the middle portion of a print roll 85 which is wrapped around a plastic former 86. An end cap 89 is provided at the other end of the print roll 85 so as to fasten the print roll and batteries firmly to the ink supply mechanism.

The solenoid coil is interconnected (not shown) to interconnects 97, 98 (FIG. 8) which include leaf spring ends for interconnection with electrical contacts on the Flex PCB so as to provide for electrical control of the solenoid.

Turning now to FIGS. 17-19 the next step in the construction process is the insertion of the relevant gear trains into the side of the camera chassis. FIG. 17 illustrates a front view, FIG. 18 illustrates a rear view and FIG. 19 also illustrates a rear view. The first gear train comprising gear wheels 22, 23 is utilized for driving the guillotine blade with the gear wheel 23 engaging the gear wheel 65 of FIG. 8. The second gear train comprising gear wheels 24, 25 and 26 engage one end of the print roller 61 of FIG. 8. As best indicated in FIG. 18, the gear wheels mate with corresponding pins on the surface of the chassis with the gear wheel 26 being snap fitted into corresponding mating hole 27.

Next, as illustrated in FIG. 20, the assembled platten unit 60 is then inserted between the print roll 85 and aluminum cutting blade 43.

Turning now to FIG. 21, by way of illumination, there is illustrated the electrically interactive components of the camera system. As noted previously, the components are based around a Flex PCB board and include a TAB film 58 which interconnects the printhead 102 with the image sensor and processing chip 48. Power is supplied by two AA type batteries 83, 84 and a paper drive stepper motor 16 is provided in addition to a rotary guillotine motor 17.

An optical element 31 is provided for snapping into a top portion of the chassis 12. The optical element 31 includes portions defining an optical view finder 32, 33 which are slotted into mating portions 35, 36 in view finder channel 37. Also provided in the optical element 31 is a lensing system 38 for magnification of the prints left number in addition to an optical pipe element 39 for piping light from the LED 5 for external display.

Turning next to FIG. 22, the assembled unit 90 is then inserted into a front outer case 91 which includes button 4 for activation of printouts.

Turning now to FIG. 23, next, the unit 90 is provided with a snap-on back cover 93 which includes a slot 6 and copy print button 7. A wrapper label containing instructions and advertising (not shown) is then wrapped around the outer surface of the camera system and pinch clamped to the cover by means of clamp strip 96 which can comprise a flexible plastic or rubber strip.

Subsequently, the preferred embodiment is ready for use as a one time use camera system that provides for instant output images on demand. It will be evident that the preferred embodiment further provides for a refillable camera system. A used camera can be collected and its outer plastic cases removed and recycled. A new paper roll and batteries can be added and the ink cartridge refilled. A series of automatic test routines can then be carried out to ensure that the printer is properly operational. Further, in order to ensure only authorized refills are conducted so as to enhance quality, routines in the on-chip program ROM can be executed such that the camera authenticates the refilling station using a secure protocol. Upon authentication, the camera can reset an internal paper count and an external case can be fitted on the camera system with a new outer label. Subsequent packing and shipping can then take place.

It will be further readily evident to those skilled in the art that the program ROM can be modified so as to allow for a variety of digital processing routines. In addition to the digitally enhanced photographs optimized for mainstream consumer preferences, various other models can readily be provided through mere re-programming of the program ROM. For example, a sepia classic old fashion style output can be provided through a remapping of the color mapping function. A further alternative is to provide for black and white outputs again through a suitable color remapping algorithm. Minimum color can also be provided to add a touch of color to black and white prints to produce the effect that was traditionally used to colorize black and white photos. Further, passport photo output can be provided through suitable address remappings within the address generators. Further, edge filters can be utilized as is known in the field of image processing to produce sketched art styles. Further, classic wedding borders and designs can be placed around an output image in addition to the provision of relevant clip arts. For example, a wedding style camera might be provided. Further, a panoramic mode can be provided so as to output the well known panoramic format of images. Further, a postcard style output can be provided through the printing of postcards including postage on the back of a print roll surface. Further, cliparts can be provided for special events such as Halloween, Christmas etc. Further, kaleidoscopic effects can be provided through address remappings and wild color effects can be provided through remapping of the color lookup table. Many other forms of special event cameras can be provided for example, cameras dedicated to the Olympics, movie tie-ins, advertising and other special events.

The operational mode of the camera can be programmed so that upon the depressing of the take photo a first image is sampled by the sensor array to determine irrelevant parameters. Next a second image is again captured which is utilized for the output. The captured image is then manipulated in accordance with any special requirements before being initially output on the paper roll. The LED light is then activated for a predetermined time during which the DRAM is refreshed so as to retain the image. If the print copy button is depressed during this predetermined time interval, a further copy of the photo is output. After the predetermined time interval where no use of the camera has occurred, the onboard CPU shuts down all power to the camera system until such time as the take button is again activated. In this way, substantial power savings can be realized.

Ink Jet Technologies

The embodiments of the invention use an ink jet printer type device. Of course many different devices could be used. However presently popular ink jet printing technologies are unlikely to be suitable.

The most significant problem with thermal inkjet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water to produce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal inkjet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out.

The most significant problem with piezoelectric inkjet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuator must be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per print head, but is a major impediment to the fabrication of pagewidth print heads with 19,200 nozzles.

Ideally, the inkjet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new inkjet technologies have been created. The target features include:

low power (less than 10 Watts)

high resolution capability (1,600 dpi or more)

photographic quality output

low manufacturing cost

small size (pagewidth times minimum cross section)

high speed (<2 seconds per page).

All of these features can be met or exceeded by the inkjet systems described below with differing levels of difficulty, forty-five different inkjet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table below.

The inkjet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems

For ease of manufacture using standard process equipment, the printhead is designed to be a monolithic 0.5 micron CMOS chip with MEMS post processing. For color photographic applications, the print head is 100 mm long, with a width which depends upon the inkjet type. The smallest print head designed is IJ38, which is 0.35 mm wide, giving a chip area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry.

Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding.

CROSS-REFERENCED APPLICATIONS

The following table is a guide to cross-referenced patent applications filed concurrently herewith and discussed hereinafter with the reference being utilized in subsequent tables when referring to a particular case:

Docket No. Reference Title IJ01US IJ01 Radiant Plunger Ink Jet Printer IJ02US IJ02 Electrostatic Ink Jet Printer IJ03US IJ03 Planar Thermoelastic Bend Actuator Ink Jet IJ04US IJ04 Stacked Electrostatic Ink Jet Printer IJ05US IJ05 Reverse Spring Lever Ink Jet Printer IJ06US IJ06 Paddle Type Ink Jet Printer IJ07US IJ07 Permanent Magnet Electromagnetic Ink Jet Printer IJ08US IJ08 Planar Swing Grill Electromagnetic Ink Jet Printer IJ09US IJ09 Pump Action Refill Ink Jet Printer IJ10US IJ10 Pulsed Magnetic Field Ink Jet Printer IJ11US IJ11 Two Plate Reverse Firing Electromagnetic Ink Jet Printer IJ12US IJ12 Linear Stepper Actuator Ink Jet Printer IJ13US IJ13 Gear Driven Shutter Ink Jet Printer IJ14US IJ14 Tapered Magnetic Pole Electromagnetic Ink Jet Printer IJ15US IJ15 Linear Spring Electromagnetic Grill Ink Jet Printer IJ16US IJ16 Lorenz Diaphragm Electromagnetic Ink Jet Printer IJ17US IJ17 PTFE Surface Shooting Shuttered Oscillating Pressure Ink Jet Printer IJ18US IJ18 Buckle Grip Oscillating Pressure Ink Jet Printer IJ19US IJ19 Shutter Based Ink Jet Printer IJ20US IJ20 Curling Calyx Thermoelastic Ink Jet Printer IJ21US IJ21 Thermal Actuated Ink Jet Printer IJ22US IJ22 Iris Motion Ink Jet Printer IJ23US IJ23 Direct Firing Thermal Bend Actuator Ink Jet Printer IJ24US IJ24 Conductive PTFE Ben Activator Vented Ink Jet Printer IJ25US IJ25 Magnetostrictive Ink Jet Printer IJ26US IJ26 Shape Memory Alloy Ink Jet Printer IJ27US IJ27 Buckle Plate Ink Jet Printer IJ28US IJ28 Thermal Elastic Rotary Impeller Ink Jet Printer IJ29US IJ29 Thermoelastic Bend Actuator Ink Jet Printer IJ30US IJ30 Thermoelastic Bend Actuator Using PTFE and Corrugated Copper Ink Jet Printer IJ31US IJ31 Bend Actuator Direct Ink Supply Ink Jet Printer IJ32US IJ32 A High Young's Modulus Thermoelastic Ink Jet Printer IJ33US IJ33 Thermally actuated slotted chamber wall ink jet printer IJ34US IJ34 Ink Jet Printer having a thermal actuator comprising an external coiled spring IJ35US IJ35 Trough Container Ink Jet Printer IJ36US IJ36 Dual Chamber Single Vertical Actuator Ink Jet IJ37US IJ37 Dual Nozzle Single Horizontal Fulcrum Actuator Ink Jet IJ38US IJ38 Dual Nozzle Single Horizontal Actuator Ink Jet IJ39US IJ39 A single bend actuator cupped paddle ink jet printing device IJ40US IJ40 A thermally actuated ink jet printer having a series of thermal actuator units IJ41US IJ41 A thermally actuated ink jet printer including a tapered heater element IJ42US IJ42 Radial Back-Curling Thermoelastic Ink Jet IJ43US IJ43 Inverted Radial Back-Curling Thermoelastic Ink Jet IJ44US IJ44 Surface bend actuator vented ink supply ink jet printer IJ45US IJ45 Coil Acutuated Magnetic Plate Ink Jet Printer

Tables of Drop-on-Demand Inkjets

Eleven important characteristics of the fundamental operation of individual inkjet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee.

The following tables form the axes of an eleven dimensional table of inkjet types.

Actuator mechanism (18 types)

Basic operation mode (7 types)

Auxiliary mechanism (8 types)

Actuator amplification or modification method (17 types)

Actuator motion (19 types)

Nozzle refill method (4 types)

Method of restricting back-flow through inlet (10 types)

Nozzle clearing method (9 types)

Nozzle plate construction (9 types)

Drop ejection direction (5 types)

Ink type (7 types)

The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of inkjet nozzle. While not all of the possible combinations result in a viable inkjet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain inkjet types have been investigated in detail. These are designated IJ01 to IJ45 above.

Other inkjet configurations can readily be derived from these forty-five examples by substituting alternative configurations along one or more of the eleven axes. Most of the IJ01 to IJ45 examples can be made into inkjet print heads with characteristics superior to any currently available inkjet technology.

Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, a printer may be listed more than once in a table, where it shares characteristics with more than one entry.

Suitable applications include: Home printers, Office network printers, Short run digital printers, Commercial print systems, Fabric printers, Pocket printers, Internet WWW printers, Video printers, Medical imaging, Wide format printers, Notebook PC printers, Fax machines, Industrial printing systems, Photocopiers, Photographic minilabs etc.

The information associated with the aforementioned eleven dimensional matrix are set out in the following tables.

ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS) Actuator Mechanism Description Advantages Disadvantages Examples Thermal An electrothermal heater heats the Large force generated High power Canon Bubblejet bubble ink to above boiling point, Simple construction Ink carrier limited to water 1979 Endo et al GB transferring significant heat to the No moving parts Low efficiency patent 2,007,162 aqueous ink. A bubble nucleates Fast operation High temperatures required Xerox heater-in-pit and quickly forms, expelling the Small chip area required High mechanical stress 1990 Hawkins et al ink. for actuator Unusual materials required U.S. Pat. No. 4,899,181 The efficiency of the process is Large drive transistors Hewlett-Packard low, with typically less than Cavitation causes actuator failure TIJ 1982 Vaught et 0.05% of the electrical energy Kogation reduces bubble formation al U.S. Pat. No. 4,490,728 being transformed into kinetic Large print heads are difficult to energy of the drop. fabricate Piezoelectric A piezoelectric crystal such as Low power consumption Very large area required for actuator Kyser et al U.S. Pat. No. lead lanthanum zirconate (PZT) is Many ink types can be Difficult to integrate with electronics 3,946,398 electrically activated, and either used High voltage drive transistors Zoltan U.S. Pat. No. expands, shears, or bends to apply Fast operation required 3,683,212 pressure to the ink, ejecting drops. High efficiency Full pagewidth print heads 1973 Stemme U.S. Pat. No. impractical due to actuator size 3,747,120 Requires electrical poling in high field Epson Stylus strengths during manufacture Tektronix IJ04 Electro- An electric field is used to Low power consumption Low maximum strain (approx. 0.01%) Seiko Epson, Usui strictive activate electrostriction in relaxor Many ink types can be Large area required for actuator due et all JP 253401/96 materials such as lead lanthanum used to low strain IJ04 zirconate titanate (PLZT) or lead Low thermal expansion Response speed is marginal (~ 10 μs) magnesium niobate (PMN). Electric field strength High voltage drive transistors required (approx. 3.5 required V/μm) can be generated Full pagewidth print heads without difficulty impractical due to actuator size Does not require electrical poling Ferroelectric An electric field is used to induce Low power consumption Difficult to integrate with electronics IJ04 a phase transition between the Many ink types can be Unusual materials such as PLZSnT antiferroelectric (AFE) and used are required ferroelectric (FE) phase. Fast operation (<1 μs) Actuators require a large area Perovskite materials such as tin Relatively high modified lead lanthanum longitudinal strain zirconate titanate (PLZSnT) High efficiency exhibit large strains of up to 1% Electric field strength of associated with the AFE to FE around 3 V/μm can be phase transition. readily provided Electrostatic Conductive plates are separated Low power consumption Difficult to operate electrostatic IJ02, IJ04 plates by a compressible or fluid Many ink types can be devices in an aqueous environment dielectric (usually air). Upon used The electrostatic actuator will application of a voltage, the plates Fast operation normally need to be separated from attract each other and displace the ink ink, causing drop ejection. The Very large area required to achieve conductive plates may be in a high forces comb or honeycomb structure, or High voltage drive transistors may be stacked to increase the surface required area and therefore the force. Full pagewidth print heads are not competitive due to actuator size Electrostatic A strong electric field is applied Low current consumption High voltage required 1989 Saito et al, pull on ink to the ink, whereupon electrostatic Low temperature May be damaged by sparks due to air U.S. Pat. No. 4,799,068 attraction accelerates the ink breakdown 1989 Miura et al, towards the print medium. Required field strength increases as U.S. Pat. No. 4,810,954 the drop size decreases Tone-jet High voltage drive transistors required Electrostatic field attracts dust Permanent An electromagnet directly attracts Low power consumption Complex fabrication IJ07, IJ10 magnet a permanent magnet, displacing Many ink types can be Permanent magnetic material such as electro- ink and causing drop ejection. used Neodymium Iron Boron (NdFeB) magnetic Rare earth magnets with a field Fast operation required. strength around 1 Tesla can be High efficiency High local currents required used. Examples are: Samarium Easy extension from single Copper metalization should be used Cobalt (SaCo) and magnetic nozzles to pagewidth print for long electromigration lifetime and materials in the neodymium iron heads low resistivity boron family (NdFeB, Pigmented inks are usually infeasible NdDyFeBNb, NdDyFeB, etc) Operating temperature limited to the Curie temperature (around 540 K) Soft magnetic A solenoid induced a magnetic Low power consumption Complex fabrication IJ01, IJ05, IJ08, core electro- field in a soft magnetic core or Many ink types can be Materials not usually present in a IJ10 magnetic yoke fabricated from a ferrous used CMOS fab such as NiFe, CoNiFe, or IJ12, IJ14, IJ15, material such as electroplated iron Fast operation CoFe are required IJ17 alloys such as CoNiFe [1], CoFe, High efficiency High local currents required or NiFe alloys. Typically, the soft Easy extension from single Copper metalization should be used magnetic material is in two parts, nozzles to pagewidth print for long electromigration lifetime and which are normally held apart by heads low resistivity a spring. When the solenoid is Electroplating is required actuated, the two parts attract, High saturation flux density is displacing the ink, required (2.0-2.1 T is achievable with CoNiFe [1]) Magnetic The Lorenz force acting on a Low power consumption Force acts as a twisting motion IJ06, IJ11, IJ13, Lorenz force current carrying wire in a Many ink types can be Typically, only a quarter of the IJ16 magnetic field is utilized. used solenoid length provides force in a This allows the magnetic field to Fast operation useful direction be supplied externally to the print High efficiency High local currents required head, for example with rare earth Easy extension from single Copper metalization should be used permanent magnets. nozzles to pagewidth print for long electromigration lifetime and Only the current carrying wire heads low resistivity need be fabricated on the print- Pigmented inks are usually infeasible head, simplifying materials requirements. Magneto- The actuator uses the giant Many ink types can be Force acts as a twisting motion Fischenbeck, U.S. Pat. No. striction magnetostrictive effect of used Unusual materials such as Terfenol-D 4,032,929 materials such as Terfenol-D (an Fast operation are required IJ25 alloy of terbium, dysprosium and Easy extension from single High local currents required iron developed at the Naval nozzles to pagewidth print Copper metalization should be used Ordnance Laboratory, hence Ter- heads for long electromigration lifetime and Fe-NOL). For best efficiency, the High force is available low resistivity actuator should be pre-stressed to Pre-stressing may be required approx. 8 MPa. Surface Ink under positive pressure is held Low power consumption Requires supplementary force to Silverbrook, EP tension in a nozzle by surface tension. Simple construction effect drop separation 0771 658 A2 and reduction The surface tension of the ink is No unusual materials Requires special ink surfactants related patent reduced below the bubble required in fabrication Speed may be limited by surfactant applications threshold, causing the ink to High efficiency properties egress from the nozzle. Easy extension from single nozzles to pagewidth print heads Viscosity The ink viscosity is locally Simple construction Requires supplementary force to Silverbrook, EP reduction reduced to select which drops are No unusual materials effect drop separation 0771 658 A2 and to be ejected. A viscosity required in fabrication Requires special ink viscosity related patent reduction can be achieved Easy extension from single properties applications electrothermally with most inks, nozzles to pagewidth print High speed is difficult to achieve but special inks can be engineered heads Requires oscillating ink pressure for a 100:1 viscosity reduction. A high temperature difference (typically 80 degrees) is required Acoustic An acoustic wave is generated and Can operate without a Complex drive circuitry 1993 Hadimioglu et focussed upon the drop ejection nozzle plate Complex fabrication al, EUP 550,192 region. Low efficiency 1993 Elrod et al, Poor control of drop position EUP 572,220 Poor control of drop volume Thermoelastic An actuator which relies upon Low power consumption Efficient aqueous operation requires a IJ03, IJ09, IJ17, bend actuator differential thermal expansion Many ink types can be thermal insulator on the hot side IJ18 upon Joule heating is used. used Corrosion prevention can be difficult IJ19, IJ20, IJ21, Simple planar fabrication Pigmented inks may be infeasible, as IJ22 Small chip area required pigment particles may jam the bend IJ23, IJ24, IJ27, for each actuator actuator IJ28 Fast operation IJ29, IJ30, IJ31, High efficiency IJ32 CMOS compatible IJ33, IJ34, IJ35, voltages and currents IJ36 Standard MEMS processes IJ37, IJ38, IJ39, can be used IJ40 Easy extension from single IJ41 nozzles to pagewidth print heads High CTE A material with a very high High force can be Requires special material (e.g. PTFE) IJ09, IJ17, IJ18, thermoelastic coefficient of thermal expansion generated Requires a PTFE deposition process, IJ20 actuator (CTE) such as PTFE is a candidate for which is not yet standard in ULSI fabs IJ21, IJ22, IJ23, polytetrafluoroethylene (PTFE) is low dielectric constant PTFE deposition cannot be followed IJ24 used. As high CTE materials are insulation in ULSI with high temperature (above 350° C.) IJ27, IJ28, IJ29, usually non-conductive, a heater Very low power processing IJ30 fabricated from a conductive consumption Pigmented inks may be infeasible, as IJ31, IJ42, IJ43, material is incorporated. A 50 μm Many ink types can be pigment particles may jam the bend IJ44 long PTFE bend actuator with used actuator polysilicon heater and 15 mW Simple planar fabrication power input can provide 180 μN Small chip area required force and 10 μm deflection. for each actuator Actuator motions include: Fast operation Bend High efficiency Push CMOS compatible Buckle voltages and currents Rotate Easy extension from single nozzles to pagewidth print heads Conductive A polymer with a high coefficient High force can be Requires special materials IJ24 polymer of thermal expansion (such as generated development (High CTE conductive thermoelastic PTFE) is doped with conducting Very low power polymer) actuator substances to increase its consumption Requires a PTFE deposition process, conductivity to about 3 orders of Many ink types can be which is not yet standard in ULSI fabs magnitude below that of copper. used PTFE deposition cannot be followed The conducting polymer expands Simple planar fabrication with high temperature (above 350° C.) when resistively heated. Small chip area required processing Examples of conducting dopants for each actuator Evaporation and CVD deposition include: Fast operation techniques cannot be used Carbon nanotubes High efficiency Pigmented inks may be infeasible, as Metal fibers CMOS compatible pigment particles may jam the bend Conductive polymers such as voltages and currents actuator doped polythiophene Easy extension from single Carbon granules nozzles to pagewidth print heads Shape memory A shape memory alloy such as High force is available Fatigue limits maximum number of IJ26 alloy TiNi (also known as Nitinol - (stresses of hundreds of cycles Nickel Titanium alloy developed MPa) Low strain (1%) is required to extend at the Naval Ordnance Large strain is available fatigue resistance Laboratory) is thermally switched (more than 3%) Cycle rate limited by heat removal between its weak martensitic state High corrosion resistance Requires unusual materials (TiNi) and its high stiffness austenic Simple construction The latent heat of transformation must state. The shape of the actuator in Easy extension from single be provided its martensitic state is deformed nozzles to pagewidth print High current operation relative to the austenic shape. The heads Requires pre-stressing to distort the shape change causes ejection of a Low voltage operation martensitic state drop. Linear Linear magnetic actuators include Linear Magnetic actuators Requires unusual semiconductor IJ12 Magnetic the Linear Induction Actuator can be constructed with materials such as soft magnetic alloys Actuator (LIA), Linear Permanent Magnet high thrust, long travel, (e.g. CoNiFe [1]) Synchronous Actuator (LPMSA), and high efficiency using Some varieties also require permanent Linear Reluctance Synchronous planar semiconductor magnetic materials such as Actuator (LRSA), Linear fabrication techniques Neodymium iron boron (NdFeB) Switched Reluctance Actuator Long actuator travel is Requires complex multi-phase drive (LSRA), and the Linear Stepper available circuitry Actuator (LSA). Medium force is available High current operation Low voltage operation

BASIC OPERATION MODE Operational mode Description Advantages Disadvantages Examples Actuator This is the simplest mode of Simple operation Drop repetition rate is usually limited Thermal inkjet directly operation: the actuator directly No external fields required to less than 10 KHz. However, this is Piezoelectric inkjet pushes ink supplies sufficient kinetic energy Satellite drops can be not fundamental to the method, but is IJ01, IJ02, IJ03, to expel the drop. The drop must avoided if drop velocity is related to the refill method normally IJ04 have a sufficient velocity to overcome less than 4 m/s used IJ05, IJ06, IJ07, the surface tension. Can be efficient, All of the drop kinetic energy must be IJ09 depending upon the provided by the actuator IJ11, IJ12, IJ14, actuator used Satellite drops usually form if drop IJ16 velocity is greater than 4.5 m/s IJ20, IJ22, IJ23, IJ24 IJ25, IJ26, IJ27, IJ28 IJ29, IJ30, IJ31, IJ32 IJ33, IJ34, IJ35, IJ36 IJ37, IJ38, IJ39, IJ40 IJ41, IJ42, IJ43, IJ44 Proximity The drops to be printed are Very simple print head Requires close proximity between the Silverbrook, EP selected by some manner (e.g. fabrication can be used print head and the print media or 0771 658 A2 and thermally induced surface tension The drop selection means transfer roller related patent reduction of pressurized ink). does not need to provide the May require two print heads printing applications Selected drops are separated from energy required to alternate rows of the image the ink in the nozzle by contact separate the drop from the Monolithic color print heads are with the print medium or a nozzle difficult transfer roller. Electrostatic The drops to be printed are Very simple print head Requires very high electrostatic field Silverbrook, EP pull on ink selected by some manner (e.g. fabrication can be used Electrostatic field for small nozzle 0771 658 A2 and thermally induced surface tension The drop selection means sizes is above air breakdown related patent reduction of pressurized ink). does not need to provide Electrostatic field may attract dust applications Selected drops are separated from the energy required to Tone-Jet the ink in the nozzle by a strong separate the drop from the electric field. nozzle Magnetic pull The drops to be printed are Very simple print head Requires magnetic ink Silverbrook, EP on ink selected by some manner (e.g. fabrication can be used Ink colors other than black are 0771 658 A2 and thermally induced surface tension The drop selection means difficult related patent reduction of pressurized ink). does not need to provide Requires very high magnetic fields applications Selected drops are separated from the energy required to the ink in the nozzle by a strong separate the drop from the magnetic field acting on the nozzle magnetic ink. Shutter The actuator moves a shutter to High speed (>50 KHz) Moving parts are required IJ13, IJ17, IJ21 block ink flow to the nozzle. The operation can be achieved Requires ink pressure modulator ink pressure is pulsed at a due to reduced refill time Friction and wear must be considered multiple of the drop ejection Drop timing can be very Stiction is possible frequency. accurate The actuator energy can be very low Shuttered grill The actuator moves a shutter to Actuators with small travel Moving parts are required IJ08, IJ15, IJ18, block ink flow through a grill to can be used Requires ink pressure modulator IJ19 the nozzle. The shutter movement Actuators with small force Friction and wear must be considered need only be equal to the width of can be used Stiction is possible the grill holes. High speed (>50 KHz) operation can be achieved Pulsed A pulsed magnetic field attracts Extremely low energy Requires an external pulsed magnetic IJ10 magnetic pull an ‘ink pusher’ at the drop operation is possible field on ink pusher ejection frequency. An actuator No heat dissipation Requires special materials for both the controls a catch, which prevents problems actuator and the ink pusher the ink pusher from moving when Complex construction a drop is not to be ejected.

AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES) Auxiliary Mechanism Description Advantages Disadvantages Examples None The actuator directly fires the ink Simplicity of construction Drop ejection energy must be Most inkjets, drop, and there is no external field Simplicity of operation supplied by individual nozzle actuator including or other mechanism required. Small physical size piezoelectric and thermal bubble. IJ01-IJ07, IJ09, IJ11 IJ12, IJ14, IJ20, IJ22 IJ23-IJ45 Oscillating ink The ink pressure oscillates, Oscillating ink pressure Requires external ink pressure Silverbrook, EP pressure providing much of the drop can provide a refill pulse, oscillator 0771 658 A2 and (including ejection energy. The actuator allowing higher operating Ink pressure phase and amplitude related patent acoustic selects which drops are to be fired by speed must be carefully controlled applications stimulation) selectively blocking or The actuators may operate Acoustic reflections in the ink IJ08, IJ13, IJ15, enabling nozzles. The ink pressure with much lower energy chamber must be designed for IJ17 oscillation may be achieved by Acoustic lenses can be IJ18, IJ19, IJ21 vibrating the print head, or used to focus the sound on the preferably by an actuator in the ink nozzles supply. Media The print head is placed in close Low power Precision assembly required Silverbrook, EP proximity proximity to the print medium. High accuracy Paper fibers may cause problems 0771 658 A2 and Selected drops protrude from the Simple print head Cannot print on rough substrates related patent print head further than unselected construction applications drops, and contact the print medium. The drop soaks into the medium fast enough to cause drop separation. Transfer roller Drops are printed to a transfer High accuracy Bulky Silverbrook, EP roller instead of straight to the Wide range of print Expensive 0771 658 A2 and print medium. A transfer roller substrates can be used Complex construction related patent can also be used for proximity Ink can be dried on the applications drop separation. transfer roller Tektronix hot melt piezoelectric inkjet Any of the IJ series Electrostatic An electric field is used to Low power Field strength required for separation Silverbrook, EP accelerate selected drops towards Simple print head of small drops is near or above air 0771 658 A2 and the print medium. construction breakdown related patent applications Tone-Jet Direct A magnetic field is used to Low power Requires magnetic ink Silverbrook, EP magnetic field accelerate selected drops of Simple print head Requires strong magnetic field 0771 658 A2 and magnetic ink towards the print medium. construction related patent applications Cross The print head is placed in a Does not require magnetic Requires external magnet IJ06, IJ16 magnetic field constant magnetic field. The materials to be integrated Current densities may be high, Lorenz force in a current carrying in the print head resulting in electromigration problems wire is used to move the actuator. manufacturing process Pulsed A pulsed magnetic field is used to Very low power operation Complex print head construction IJ10 magnetic field cyclically attract a paddle, which is possible Magnetic materials required in print pushes on the ink. A small Small print head size head actuator moves a catch, which selectively prevents the paddle from moving.

ACTUATOR AMPLIFICATION OR MODIFICATION METHOD Actuator amplification Description Advantages Disadvantages Examples None No actuator mechanical Operational simplicity Many actuator mechanisms have Thermal Bubble amplification is used. The actuator insufficient travel, or insufficient Inkjet directly drives the drop ejection force, to efficiently drive the drop IJ01, IJ02, IJ06, process. ejection process IJ07 IJ16, IJ25, IJ26 Differential An actuator material expands Provides greater travel in a High stresses are involved Piezoelectric expansion more on one side than on the reduced print head area Care must be taken that the materials IJ03, IJ09, IJ17-IJ24 bend actuator other. The expansion may be The bend actuator converts do not delaminate IJ27, IJ29-IJ39, thermal, piezoelectric, a high force low travel Residual bend resulting from high IJ42, magnetostrictive, or other actuator mechanism to temperature or high stress during IJ43, IJ44 mechanism. high travel, lower force formation mechanism. Transient bend A trilayer bend actuator where the Very good temperature High stresses are involved IJ40, IJ41 actuator two outside layers are identical. stability Care must be taken that the materials This cancels bend due to ambient High speed, as a new drop do not delaminate temperature and residual stress. can be fired before heat The actuator only responds to dissipates transient heating of one side or the Cancels residual stress of other. formation Actuator stack A series of thin actuators are Increased travel Increased fabrication complexity Some piezoelectric stacked. This can be appropriate Reduced drive voltage Increased possibility of short circuits ink jets where actuators require high due to pinholes IJ04 electric field strength, such as electrostatic and piezoelectric actuators. Multiple Multiple smaller actuators are Increases the force Actuator forces may not add linearly, IJ12, IJ13, IJ18, actuators used simultaneously to move the available from an actuator reducing efficiency IJ20 ink. Each actuator need provide Multiple actuators can be IJ22, IJ28, IJ42, only a portion of the force positioned to control ink IJ43 required. flow accurately Linear Spring A linear spring is used to Matches low travel Requires print head area for the spring IJ15 transform a motion with small actuator with higher travel travel and high force into a longer requirements travel, lower force motion. Non-contact method of motion transformation Reverse spring The actuator loads a spring. When Better coupling to the ink Fabrication complexity IJ05, IJ11 the actuator is turned off, the High stress in the spring spring releases. This can reverse the force/distance curve of the actuator to make it compatible with the force/time requirements of the drop ejection. Coiled A bend actuator is coiled to Increases travel Generally restricted to planar IJ17, IJ21, IJ34, actuator provide greater travel in a reduced Reduces chip area implementations due to extreme IJ35 chip area. Planar implementations fabrication difficulty in other are relatively easy to orientations. fabricate. Flexure bend A bend actuator has a small Simple means of Care must be taken not to exceed the IJ10, IJ19, IJ33 actuator region near the fixture point, increasing travel of a bend elastic limit in the flexure area which flexes much more readily actuator Stress distribution is very uneven than the remainder of the actuator. Difficult to accurately model with The actuator flexing is effectively finite element analysis converted from an even coiling to an angular bend, resulting in greater travel of the actuator tip. Gears Gears can be used to increase Low force, low travel Moving parts are required IJ13 travel at the expense of duration. actuators can be used Several actuator cycles are required Circular gears, rack and pinion, Can be fabricated using More complex drive electronics ratchets, and other gearing standard surface MEMS Complex construction methods can be used. processes Friction, friction, and wear are possible Catch The actuator controls a small Very low actuator energy Complex construction IJ10 catch. The catch either enables or Very small actuator size Requires external force disables movement of an ink Unsuitable for pigmented inks pusher that is controlled in a bulk manner. Buckle plate A buckle plate can be used to Very fast movement Must stay within elastic limits of the S. Hirata et al, “An change a slow actuator into a fast achievable materials for long device life Ink-jet Head . . . ”, motion. It can also convert a high High stresses involved Proc. IEEE MEMS, force, low travel actuator into a Generally high power requirement February 1996, pp 418-423. high travel, medium force motion. IJ18, IJ27 Tapered A tapered magnetic pole can Linearizes the magnetic Complex construction IJ14 magnetic pole increase travel at the expense of force/distance curve force. Lever A lever and fulcrum is used to Matches low travel High stress around the fulcrum IJ32, IJ36, IJ37 transform a motion with small actuator with higher travel travel and high force into a requirements motion with longer travel and Fulcrum area has no linear lower force. The lever can also movement, and can be reverse the direction of travel. used for a fluid seal Rotary The actuator is connected to a High mechanical Complex construction IJ28 impeller rotary impeller. A small angular advantage Unsuitable for pigmented inks deflection of the actuator results The ratio of force to travel in a rotation of the impeller vanes, of the actuator can be which push the ink against matched to the nozzle stationary vanes and out of the requirements by varying nozzle. the number of impeller vanes Acoustic lens A refractive or diffractive (e.g. No moving parts Large area required 1993 Hadimioglu et zone plate) acoustic lens is used to Only relevant for acoustic ink jets al, EUP 550,192 concentrate sound waves. 1993 Elrod et al, EUP 572,220 Sharp A sharp point is used to Simple construction Difficult to fabricate using standard Tone-jet conductive concentrate an electrostatic field. VLSI processes for a surface ejecting point ink-jet Only relevant for electrostatic ink jets

ACTUATOR MOTION Actuator motion Description Advantages Disadvantages Examples Volume The volume of the actuator Simple construction in the High energy is typically required to Hewlett-Packard expansion changes, pushing the ink in all case of thermal ink jet achieve volume expansion. This leads Thermal Inkjet directions. to thermal stress, cavitation, and Canon Bubblejet kogation in thermal ink jet implementations Linear, normal The actuator moves in a direction Efficient coupling to ink High fabrication complexity may be IJ01, IJ02, IJ04, to chip surface normal to the print head surface. drops ejected normal to the required to achieve perpendicular IJ07 The nozzle is typically in the line surface motion IJ11, IJ14 of movement. Linear, parallel The actuator moves parallel to the Suitable for planar Fabrication complexity IJ12, IJ13, IJ15, to chip surface print head surface. Drop ejection fabrication Friction IJ33, may still be normal to the surface. Stiction IJ34, IJ35, IJ36 Membrane An actuator with a high force but The effective area of the Fabrication complexity 1982 Howkins U.S. push small area is used to push a stiff actuator becomes the Actuator size Pat. No. 4,459,601 membrane that is in contact with membrane area Difficulty of integration in a VLSI the ink. process Rotary The actuator causes the rotation of Rotary levers may be used Device complexity IJ05, IJ08, IJ13, some element, such a grill or to increase travel May have friction at a pivot point IJ28 impeller Small chip area requirements Bend The actuator bends when A very small change in Requires the actuator to be made from 1970 Kyser et al energized. This may be due to dimensions can be at least two distinct layers, or to have U.S. Pat. No. 3,946,398 differential thermal expansion, converted to a large a thermal difference across the 1973 Stemme U.S. Pat. No. piezoelectric expansion, motion. actuator 3,747,120 magnetostriction, or other form of IJ03, IJ09, IJ10, relative dimensional change. IJ19 IJ23, IJ24, IJ25, IJ29 IJ30, IJ31, IJ33, IJ34 IJ35 Swivel The actuator swivels around a Allows operation where Inefficient coupling to the ink motion IJ06 central pivot. This motion is the net linear force on the suitable where there are opposite paddle is zero forces applied to opposite sides of Small chip area the paddle, e.g. Lorenz force. requirements Straighten The actuator is normally bent, and Can be used with shape Requires careful balance of stresses to IJ26, IJ32 straightens when energized. memory alloys where the ensure that the quiescent bend is austenic phase is planar accurate Double bend The actuator bends in one One actuator can be Difficult to make the drops IJ36, IJ37, IJ38 direction when one element is used to power two ejected by both bend directions energized, and bends the other nozzles. identical. way when another element is Reduced chip size. A small efficiency loss compared energized. Not sensitive to to equivalent single bend ambient temperature actuators. Shear Energizing the actuator causes a Can increase the Not readily applicable to other 1985 Fishbeck shear motion in the actuator effective travel of actuator mechanisms U.S. Pat. No. 4,584,590 material. piezoelectric actuators Radial The actuator squeezes an ink Relatively easy to High force required 1970 Zoltan constriction reservoir, forcing ink from a fabricate single Inefficient U.S. Pat. No. 3,683,212 constricted nozzle. nozzles from glass Difficult to integrate with VLSI tubing as macroscopic processes structures Coil/uncoil A coiled actuator uncoils or coils Easy to fabricate as a Difficult to fabricate for non- IJ17, IJ21, IJ34, more tightly. The motion of the planar VLSI process planar devices IJ35 free end of the actuator ejects the Small area required, Poor out-of-plane stiffness ink. therefore low cost Bow The actuator bows (or buckles) in Can increase the speed Maximum travel is constrained IJ16, IJ18, IJ27 the middle when energized. of travel High force required Mechanically rigid Push-Pull Two actuators control a shutter. The structure is pinned Not readily suitable for inkjets IJ18 One actuator pulls the shutter, and at both ends, so has a which directly push the ink the other pushes it. high out-of-plane rigidity Curl inwards A set of actuators curl inwards to Good fluid flow to the Design complexity IJ20, IJ42 reduce the volume of ink that they region behind the enclose. actuator increases efficiency Curl outwards A set of actuators curl outwards, Relatively simple Relatively large chip area IJ43 pressurizing ink in a chamber construction surrounding the actuators, and expelling ink from a nozzle in the chamber. Iris Multiple vanes enclose a volume High efficiency High fabrication complexity IJ22 of ink. These simultaneously Small chip area Not suitable for pigmented inks rotate, reducing the volume between the vanes. Acoustic The actuator vibrates at a high The actuator can be Large area required for efficient 1993 vibration frequency. physically distant from operation at useful frequencies Hadimioglu et the ink Acoustic coupling and crosstalk al, EUP 550,192 Complex drive circuitry 1993 Elrod et al, Poor control of drop volume and EUP 572,220 position None In various ink jet designs the No moving parts Various other tradeoffs are required to Silverbrook, EP actuator does not move. eliminate moving parts 0771 658 A2 and related patent applications Tone-jet

NOZZLE REFILL METHOD Nozzle refill method Description Advantages Disadvantages Examples Surface After the actuator is energized, it Fabrication simplicity Low speed Thermal inkjet tension typically returns rapidly to its Operational simplicity Surface tension force relatively small Piezoelectric inkjet normal position. This rapid return compared to actuator force IJ01-IJ07, IJ10-IJ14 sucks in air through the nozzle Long refill time usually dominates the IJ16, IJ20, IJ22-IJ45 opening. The ink surface tension total repetition rate at the nozzle then exerts a small force restoring the meniscus to a minimum area. Shuttered Ink to the nozzle chamber is High speed Requires common ink pressure IJ08, IJ13, IJ15, oscillating ink provided at a pressure that Low actuator energy, as oscillator IJ17 pressure oscillates at twice the drop the actuator need only May not be suitable for pigmented IJ18, IJ19, IJ21 ejection frequency. When a drop open or close the shutter, inks is to be ejected, the shutter is instead of ejecting the ink opened for 3 half cycles: drop drop ejection, actuator return, and refill. Refill actuator After the main actuator has High speed, as the nozzle Requires two independent actuators IJ09 ejected a drop a second (refill) is actively refilled per nozzle actuator is energized. The refill actuator pushes ink into the nozzle chamber. The refill actuator returns slowly, to prevent its return from emptying the chamber again. Positive ink The ink is held a slight positive High refill rate, therefore a Surface spill must be prevented Silverbrook, EP pressure pressure. After the ink drop is high drop repetition rate is Highly hydrophobic print head 0771 658 A2 and ejected, the nozzle chamber fills possible surfaces are required related patent quickly as surface tension and ink applications pressure both operate to refill the Alternative for: nozzle. IJ01-IJ07, IJ10-IJ14 IJ16, IJ20, IJ22-IJ45

METHOD OF RESTRICTING BACK-FLOW THROUGH INLET Inlet back-flow restriction method Description Advantages Disadvantages Examples Long inlet channel The ink inlet channel to the nozzle Design simplicity Restricts refill rate Thermal inkjet chamber is made long and Operational simplicity May result in a relatively large chip Piezoelectric inkjet relatively narrow, relying on Reduces crosstalk area IJ42, IJ43 viscous drag to reduce inlet back- Only partially effective flow. Positive ink pressure The ink is under a positive Drop selection and Requires a method (such as a Silverbrook, EP pressure, so that in the quiescent separation forces can nozzle rim or effective 0771 658 A2 state some of the ink drop already be reduced hydrophobizing, or both) to and related protrudes from the nozzle. Fast refill time prevent flooding of the ejection patent This reduces the pressure in the surface of the print head. applications nozzle chamber which is required Possible to eject a certain volume of ink. operation of the The reduction in chamber following: pressure results in a reduction in IJ01-IJ07, IJ09-IJ12 ink pushed out through the inlet. IJ14, IJ16, IJ20, IJ22, IJ23-IJ34, IJ36-IJ41 IJ44 Baffle One or more baffles are placed in The refill rate is not as Design complexity HP Thermal Ink the inlet ink flow. When the restricted as the long May increase fabrication Jet actuator is energized, the rapid ink inlet method. complexity (e.g. Tektronix hot Tektronix movement creates eddies which Reduces crosstalk melt Piezoelectric print heads). piezoelectric ink restrict the flow through the inlet. jet The slower refill process is unrestricted, and does not result in eddies. Flexible flap In this method recently disclosed Significantly reduces Not applicable to most inkjet Canon restricts inlet by Canon, the expanding actuator back-flow for edge- configurations (bubble) pushes on a flexible flap shooter thermal ink jet Increased fabrication complexity that restricts the inlet. devices Inelastic deformation of polymer flap results in creep over extended use Inlet filter A filter is located between the ink Additional advantage Restricts refill rate IJ04, IJ12, IJ24, inlet and the nozzle chamber. The of ink filtration May result in complex IJ27 filter has a multitude of small Ink filter may be construction IJ29, IJ30 holes or slots, restricting ink flow. fabricated with no The filter also removes particles additional process which may block the nozzle. steps Small inlet The ink inlet channel to the nozzle Design simplicity Restricts refill rate IJ02, IJ37, IJ44 compared to chamber has a substantially May result in a relatively large nozzle smaller cross section than that of chip area the nozzle, resulting in easier ink Only partially effective egress out of the nozzle than out of the inlet. Inlet shutter A secondary actuator controls the Increases speed of the ink- Requires separate refill actuator and IJ09 position of a shutter, closing off jet print head operation drive circuit the ink inlet when the main actuator is energized. The inlet is The method avoids the problem of Back-flow problem is Requires careful design to minimize IJ01, IJ03, IJ05, located behind inlet back-flow by arranging the eliminated the negative pressure behind the IJ06 the ink- ink-pushing surface of the paddle IJ07, IJ10, IJ11, pushing actuator between the inlet and the IJ14 surface nozzle. IJ16, IJ22, IJ23, IJ25 IJ28, IJ31, IJ32, IJ33 IJ34, IJ35, IJ36, IJ39 IJ40, IJ41 Part of the The actuator and a wall of the ink Significant reductions in Small increase in fabrication IJ07, IJ20, IJ26, actuator chamber are arranged so that the back-flow can be achieved complexity IJ38 moves to shut motion of the actuator closes off Compact designs possible off the inlet the inlet. Nozzle In some configurations of ink jet, Ink back-flow problem is None related to ink back-flow on Silverbrook, EP actuator does there is no expansion or eliminated actuation 0771 658 A2 and not result in movement of an actuator which related patent ink back-flow may cause ink back-flow through applications the inlet. Valve-jet Tone-jet IJ08, IJ13, IJ15, IJ17 IJ18, IJ19, IJ21

NOZZLE CLEARING METHOD Nozzle Clearing method Description Advantages Disadvantages Examples Normal nozzle firing All of the nozzles are fired No added complexity on May not be sufficient to displace Most ink jet systems periodically, before the ink has a the print head dried ink IJ01-IJ07, IJ09-IJ12 chance to dry. When not in use IJ14, IJ16, IJ20, the nozzles are sealed (capped) IJ22 against air. IJ23-IJ34, IJ36-IJ45 The nozzle firing is usually performed during a special clearing cycle, after first moving the print head to a cleaning station. Extra power to In systems which heat the ink, but Can be highly effective if Requires higher drive voltage for Silverbrook, EP ink heater do not boil it under normal the heater is adjacent to clearing 0771 658 A2 and situations, nozzle clearing can be the nozzle May require larger drive transistors related patent achieved by over-powering the applications heater and boiling ink at the nozzle. Rapid The actuator is fired in rapid Does not require extra Effectiveness depends substantially May be used with: succession of succession. In some drive circuits on the print upon the configuration of the inkjet IJ01-IJ07, IJ09-IJ11 actuator configurations, this may cause head nozzle IJ14, IJ16, IJ20, pulses heat build-up at the nozzle which Can be readily controlled IJ22 boils the ink, clearing the nozzle. and initiated by digital IJ23-IJ25, IJ27-IJ34 In other situations, it may cause logic IJ36-IJ45 sufficient vibrations to dislodge clogged nozzles. Extra power to Where an actuator is not normally A simple solution where Not suitable where there is a hard May be used with: ink pushing driven to the limit of its motion, applicable limit to actuator movement IJ03, IJ09, IJ16, actuator nozzle clearing may be assisted by IJ20 providing an enhanced drive IJ23, IJ24, IJ25, signal to the actuator. IJ27 IJ29, IJ30, IJ31, IJ32 IJ39, IJ40, IJ41, IJ42 IJ43, IJ44, IJ45 Acoustic An ultrasonic wave is applied to A high nozzle clearing High implementation cost if system IJ08, IJ13, IJ15, resonance the ink chamber. This wave is of capability can be achieved does not already include an acoustic IJ17 an appropriate amplitude and May be implemented at actuator IJ18, IJ19, IJ21 frequency to cause sufficient force very low cost in systems at the nozzle to clear blockages. which already include This is easiest to achieve if the acoustic actuators ultrasonic wave is at a resonant frequency of the ink cavity. Nozzle A microfabricated plate is pushed Can clear severely clogged Accurate mechanical alignment is Silverbrook, EP clearing plate against the nozzles. The plate has nozzles required 0771 658 A2 and a post for every nozzle. The array Moving parts are required related patent of posts There is risk of damage to the nozzles applications Accurate fabrication is required Ink pressure The pressure of the ink is May be effective where Requires pressure pump or other May be used with pulse temporarily increased so that ink other methods cannot be pressure actuator all IJ series ink jets streams from all of the nozzles. used Expensive This may be used in conjunction Wasteful of ink with actuator energizing. Print head A flexible ‘blade’ is wiped across Effective for planar print Difficult to use if print head surface is Many ink jet wiper the print head surface. The blade head surfaces non-planar or very fragile systems is usually fabricated from a Low cost Requires mechanical parts flexible polymer, e.g. rubber or Blade can wear out in high volume synthetic elastomer. print systems Separate ink A separate heater is provided at Can be effective where Fabrication complexity Can be used with boiling heater the nozzle although the normal other nozzle clearing many IJ series ink drop e-ection mechanism does methods cannot be used jets not require it. The heaters do not Can be implemented at no require individual drive circuits, additional cost in some as many nozzles can be cleared inkjet configurations simultaneously, and no imaging is required.

NOZZLE PLATE CONSTRUCTION Nozzle plate construction Description Advantages Disadvantages Examples Electroformed A nozzle plate is separately Fabrication simplicity High temperatures and pressures are Hewlett Packard nickel fabricated from electroformed required to bond nozzle plate Thermal Inkjet nickel, and bonded to the print Minimum thickness constraints head chip. Differential thermal expansion Laser ablated Individual nozzle holes are No masks required Each hole must be individually Canon Bubblejet or drilled ablated by an intense UV laser in Can be quite fast formed 1988 Sercel et al., polymer a nozzle plate, which is typically a Some control over nozzle Special equipment required SPIE, Vol. 998 polymer such as polyimide or profile is possible Slow where there are many thousands Excimer Beam polysulphone Equipment required is of nozzles per print head Applications, pp. relatively low cost May produce thin burrs at exit holes 76-83 1993 Watanabe et al., U.S. Pat. No. 5,208,604 Silicon A separate nozzle plate is High accuracy is attainable Two part construction K. Bean, IEEE micromachined micromachined from single High cost Transactions on crystal silicon, and bonded to the Requires precision alignment Electron Devices, print head wafer. Nozzles may be clogged by adhesive Vol. ED-25, No. 10, 1978, pp 1185-1195 Xerox 1990 Hawkins et al., U.S. Pat. No. 4,899,181 Glass Fine glass capillaries are drawn No expensive equipment Very small nozzle sizes are difficult 1970 Zoltan U.S. Pat. No. capillaries from glass tubing. This method required to form 3,683,212 has been used for making Simple to make single Not suited for mass production individual nozzles, but is difficult nozzles to use for bulk manufacturing of print heads with thousands of nozzles. Monolithic, The nozzle plate is deposited as a High accuracy (<1 μm) Requires sacrificial layer under the Silverbrook, EP surface layer using standard VLSI Monolithic nozzle plate to form the nozzle 0771 658 A2 and micromachined deposition techniques. Nozzles Low cost chamber related patent using VLSI are etched in the nozzle plate Existing processes can be Surface may be fragile to the touch applications lithographic using VLSI lithography and used IJ01, IJ02, IJ04, processes etching. IJ11 IJ12, IJ17, IJ18, IJ20 IJ22, IJ24, IJ27, IJ28 IJ29, IJ30, IJ31, IJ32 IJ33, IJ34, IJ36, IJ37 IJ38, IJ39, IJ40, IJ41 IJ42, IJ43, IJ44 Monolithic, The nozzle plate is a buried etch High accuracy (<1 μm) Requires long etch times IJ03, IJ05, IJ06, etched stop in the wafer. Nozzle Monolithic Requires a support wafer IJ07 through chambers are etched in the front Low cost IJ08, IJ09, IJ10, substrate of the wafer, and the wafer is No differential expansion IJ13 thinned from the back side. IJ14, IJ15, IJ16, Nozzles are then etched in the IJ19 etch stop layer. IJ21, IJ23, IJ25, IJ26 No nozzle Various methods have been tried No nozzles to become Difficult to control drop position Ricoh 1995 Sekiya plate to eliminate the nozzles entirely, clogged accurately et al U.S. Pat. No. 5,412,413 to prevent nozzle clogging. These Crosstalk problems 1993 Hadimioglu et include thermal bubble al EUP 550,192 mechanisms and acoustic lens 1993 Elrod et al mechanisms EUP 572,220 Trough Each drop ejector has a trough Reduced manufacturing Drop firing direction is sensitive to IJ35 through which a paddle moves. complexity wicking. There is no nozzle plate. Monolithic Nozzle slit The elimination of nozzle holes No nozzles to become Difficult to control drop position 1989 Saito et al U.S. Pat. No. instead of and replacement by a slit clogged accurately 4,799,068 individual encompassing many actuator Crosstalk problems nozzles positions reduces nozzle clogging, but increases crosstalk due to ink surface waves

DROP EJECTION DIRECTION Ejection direction Description Advantages Disadvantages Examples Edge Ink flow is along the surface of Simple construction Nozzles limited to edge Canon (‘edge the chip, and ink drops are ejected No silicon etching High resolution is difficult Bubblejet 1979 shooter’) from the chip edge. required Fast color printing requires one Endo et al GB Good heat sinking via print head per color patent 2,007,162 substrate Xerox heater-in- Mechanically strong pit 1990 Ease of chip handing Hawkins et al U.S. Pat. No. 4,899,181 Tone-jet Surface Ink flow is along the surface of No bulk silicon Maximum ink flow is severely Hewlett- (‘roof shooter’) the chip, and ink drops are ejected etching required restricted Packard TIJ from the chip surface, normal to Silicon can make an 1982 Vaught et the plane of the chip. effective heat sink al U.S. Pat. No. Mechanical strength 4,490,728 IJ02, IJ11, IJ12, IJ20 IJ22 Through chip, Ink flow is through the chip, and High ink flow Requires bulk silicon etching Silverbrook, EP forward ink drops are ejected from the Suitable for pagewidth 0771 658 A2 (‘up shooter’) front surface of the chip. print and related High nozzle packing patent density therefore low applications manufacturing cost IJ04, IJ17, IJ18, IJ24 IJ27-IJ45 Through chip, Ink flow is through the chip, and High ink flow Requires wafer thinning IJ01, IJ03, IJ05, reverse ink drops are ejected from the rear Suitable for pagewidth Requires special handling during IJ06 (‘down surface of the chip. print manufacture IJ07, IJ08, IJ09, shooter’) High nozzle packing IJ10 density therefore low IJ13, IJ14, IJ15, manufacturing cost IJ16 IJ19, IJ21, IJ23, IJ25 IJ26 Through Ink flow is through the actuator, Suitable for Pagewidth print heads require Epson Stylus actuator which is not fabricated as part of piezoelectric print several thousand connections to Tektronix hot the same substrate as the drive heads drive circuits melt transistors. Cannot be manufactured in piezoelectric ink standard CMOS fabs jets Complex assembly required

INK TYPE Ink type Description Advantages Disadvantages Examples Aqueous, dye Water based ink which typically Environmentally friendly Slow drying Most existing contains: water, dye, surfactant, No odor Corrosive inkjets humectant, and biocide. Bleeds on paper All IJ series ink jets Modern ink dyes have high water- May strikethrough Silverbrook, EP fastness, light fastness Cockles paper 0771 658 A2 and related patent applications Aqueous, Water based ink which typically Environmentally friendly Slow drying IJ02, IJ04, IJ21, pigment contains: water, pigment, No odor Corrosive IJ26 surfactant, humectant, and Reduced bleed Pigment may clog nozzles IJ27, IJ30 biocide. Reduced wicking Pigment may clog actuator Silverbrook, EP Pigments have an advantage in Reduced strikethrough mechanisms 0771 658 A2 and reduced bleed, wicking and Cockles paper related patent strikethrough. applications Piezoelectric ink- jets Thermal ink jets (with significant restrictions) Methyl Ethyl MEK is a highly volatile solvent Very fast drying Odorous All IJ series ink jets Ketone (MEK) used for industrial printing on Prints on various Flammable difficult surfaces such as substrates such as metals aluminum cans. and plastics Alcohol Alcohol based inks can be used Fast drying Slight odor All IJ series ink jets (ethanol, 2- where the printer must operate at Operates at sub-freezing Flammable butanol, and temperatures below the freezing temperatures others) point of water. An example of this Reduced paper cockle is in-camera consumer Low cost photographic printing. Phase change The ink is solid at room No drying time-ink High viscosity Tektronix hot melt (hot melt) temperature, and is melted in the instantly freezes on the Printed ink typically has a ‘waxy’ feel piezoelectric ink jets print head before jetting. Hot melt print medium Printed pages may ‘block’ 1989 Nowak U.S. Pat. No. inks are usually wax based, with a Almost any print medium Ink temperature may be above the 4,820,346 melting point around 80° C. After can be used curie point of permanent magnets All IJ series ink jets jetting the ink freezes almost No paper cockle occurs Ink heaters consume power instantly upon contacting the print No wicking occurs Long warm-up time medium or a transfer roller. No bleed occurs No strikethrough occurs Oil Oil based inks are extensively High solubility medium High viscosity: this is a significant All IJ series ink jets used in offset printing. They have for some dyes limitation for use in inkjets, which advantages in improved Does not cockle paper usually require a low viscosity. Some characteristics on paper Does not wick through short chain and multi-branched oils (especially no wicking or cockle). paper have a sufficiently low viscosity. Oil soluble dies and pigments are Slow drying required. Microemulsion A microemulsion is a stable, self Stops ink bleed Viscosity higher than water All IJ series ink jets forming emulsion of oil, water, High dye solubility Cost is slightly higher than water and surfactant. The characteristic Water, oil, and based ink drop size is less than 100 nm, and amphiphilic soluble dies High surfactant concentration is determined by the preferred can be used required (around 5%) curvature of the surfactant. Can stabilize pigment suspensions

Ink Jet Printing

A large number of new forms of ink jet printers have been developed to facilitate alternative ink jet technologies for the image processing and data distribution system. Various combinations of ink jet devices can be included in printer devices incorporated as part of the present invention. Australian Provisional Patent Applications relating to these ink jets which are specifically incorporated by cross reference include:

Australian Provisional Number Filing Date Title PO8066 15-Jul-97 Image Creation Method and Apparatus (IJ01) PO8072 15-Jul-97 Image Creation Method and Apparatus (IJ02) PO8040 15-Jul-97 Image Creation Method and Apparatus (IJ03) PO8071 15-Jul-97 Image Creation Method and Apparatus (IJ04) PO8047 15-Jul-97 Image Creation Method and Apparatus (IJ05) PO8035 15-Jul-97 Image Creation Method and Apparatus (IJ06) PO8044 15-Jul-97 Image Creation Method and Apparatus (IJ07) PO8063 15-Jul-97 Image Creation Method and Apparatus (IJ08) PO8057 15-Jul-97 Image Creation Method and Apparatus (IJ09) PO8056 15-Jul-97 Image Creation Method and Apparatus (IJ10) PO8069 15-Jul-97 Image Creation Method and Apparatus (IJ11) PO8049 15-Jul-97 Image Creation Method and Apparatus (IJ12) PO8036 15-Jul-97 Image Creation Method and Apparatus (IJ13) PO8048 15-Jul-97 Image Creation Method and Apparatus (IJ14) PO8070 15-Jul-97 Image Creation Method and Apparatus (IJ15) PO8067 15-Jul-97 Image Creation Method and Apparatus (IJ16) PO8001 15-Jul-97 Image Creation Method and Apparatus (IJ17) PO8038 15-Jul-97 Image Creation Method and Apparatus (IJ18) PO8033 15-Jul-97 Image Creation Method and Apparatus (IJ19) PO8002 15-Jul-97 Image Creation Method and Apparatus (IJ20) PO8068 15-Jul-97 Image Creation Method and Apparatus (IJ21) PO8062 15-Jul-97 Image Creation Method and Apparatus (IJ22) PO8034 15-Jul-97 Image Creation Method and Apparatus (IJ23) PO8039 15-Jul-97 Image Creation Method and Apparatus (IJ24) PO8041 15-Jul-97 Image Creation Method and Apparatus (IJ25) PO8004 15-Jul-97 Image Creation Method and Apparatus (IJ26) PO8037 15-Jul-97 Image Creation Method and Apparatus (IJ27) PO8043 15-Jul-97 Image Creation Method and Apparatus (IJ28) PO8042 15-Jul-97 Image Creation Method and Apparatus (IJ29) PO8064 15-Jul-97 Image Creation Method and Apparatus (IJ30) PO9389 23-Sep-97 Image Creation Method and Apparatus (IJ31) PO9391 23-Sep-97 Image Creation Method and Apparatus (IJ32) PP0888 12-Dec-97 Image Creation Method and Apparatus (IJ33) PP0891 12-Dec-97 Image Creation Method and Apparatus (IJ34) PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ35) PP0873 12-Dec-97 Image Creation Method and Apparatus (IJ36) PP0993 12-Dec-97 Image Creation Method and Apparatus (IJ37) PP0890 12-Dec-97 Image Creation Method and Apparatus (IJ38) PP1398 19-Jan-98 An Image Creation Method and Apparatus (IJ39) PP2592 25-Mar-98 An Image Creation Method and Apparatus (IJ40) PP2593 25-Mar-98 Image Creation Method and Apparatus (IJ41) PP3991 9-Jun-98 Image Creation Method and Apparatus (IJ42) PP3987 9-Jun-98 Image Creation Method and Apparatus (IJ43) PP3985 9-Jun-98 Image Creation Method and Apparatus (IJ44) PP3983 9-Jun-98 Image Creation Method and Apparatus (IJ45)

Ink Jet Manufacturing

Further, the present application may utilize advanced semiconductor fabrication techniques in the construction of large arrays of ink jet printers. Suitable manufacturing techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Filing Number Date Title PO7935 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM01) PO7936 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM02) PO7937 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM03) PO8061 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM04) PO8054 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM05) PO8065 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM06) PO8055 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM07) PO8053 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM08) PO8078 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM09) PO7933 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM10) PO7950 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM11) PO7949 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM12) PO8060 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM13) PO8059 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM14) PO8073 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM15) PO8076 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM16) PO8075 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM17) PO8079 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM18) PO8050 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM19) PO8052 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM20) PO7948 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM21) PO7951 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM22) PO8074 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM23) PO7941 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM24) PO8077 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM25) PO8058 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM26) PO8051 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM27) PO8045 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM28) PO7952 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM29) PO8046 15-Jul-97 A Method of Manufacture of an Image Creation Apparatus (IJM30) PO8503 11-Aug-97 A Method of Manufacture of an Image Creation Apparatus (IJM30a) PO9390 23-Sep-97 A Method of Manufacture of an Image Creation Apparatus (IJM31) PO9392 23-Sep-97 A Method of Manufacture of an Image Creation Apparatus (IJM32) PP0889 12-Dec-97 A Method of Manufacture of an Image Creation Apparatus (IJM35) PP0887 12-Dec-97 A Method of Manufacture of an Image Creation Apparatus (IJM36) PP0882 12-Dec-97 A Method of Manufacture of an Image Creation Apparatus (IJM37) PP0874 12-Dec-97 A Method of Manufacture of an Image Creation Apparatus (IJM38) PP1396 19-Jan-98 A Method of Manufacture of an Image Creation Apparatus (IJM39) PP2591 25-Mar-98 A Method of Manufacture of an Image Creation Apparatus (IJM41) PP3989 9-Jun-98 A Method of Manufacture of an Image Creation Apparatus (IJM40) PP3990 9-Jun-98 A Method of Manufacture of an Image Creation Apparatus (IJM42) PP3986 9-Jun-98 A Method of Manufacture of an Image Creation Apparatus (IJM43) PP3984 9-Jun-98 A Method of Manufacture of an Image Creation Apparatus (IJM44) PP3982 9-Jun-98 A Method of Manufacture of an Image Creation Apparatus (IJM45)

Fluid Supply

Further, the present application may utilize an ink delivery system to the ink jet head. Delivery systems relating to the supply of ink to a series of ink jet nozzles are described in the following Australian provisional patent specifications, the disclosure of which are hereby incorporated by cross-reference:

Australian Provisional Filing Number Date Title PO8003 15-Jul-97 Supply Method and Apparatus (F1) PO8005 15-Jul-97 Supply Method and Apparatus (F2) PO9404 23-Sep-97 A Device and Method (F3)

MEMS Technology

Further, the present application may utilize advanced semiconductor microelectromechanical techniques in the construction of large arrays of ink jet printers. Suitable microelectromechanical techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Filing Number Date Title PO7943 15-Jul-97 A device (MEMS01) PO8006 15-Jul-97 A device (MEMS02) PO8007 15-Jul-97 A device (MEMS03) PO8008 15-Jul-97 A device (MEMS04) PO8010 15-Jul-97 A device (MEMS05) PO8011 15-Jul-97 A device (MEMS06) PO7947 15-Jul-97 A device (MEMS07) PO7945 15-Jul-97 A device (MEMS08) PO7944 15-Jul-97 A device (MEMS09) PO7946 15-Jul-97 A device (MEMS10) PO9393 23-Sep-97 A Device and Method (MEMS11) PP0875 12-Dec-97 A Device (MEMS12) PP0894 12-Dec-97 A Device and Method (MEMS13)

IR Technologies

Further, the present application may include the utilization of a disposable camera system such as those described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PP0895 12-Dec-97 An Image Creation Method and Apparatus (IR01) PP0870 12-Dec-97 A Device and Method (IR02) PP0869 12-Dec-97 A Device and Method (IR04) PP0887 12-Dec-97 Image Creation Method and Apparatus (IR05) PP0885 12-Dec-97 An Image Production System (IR06) PP0884 12-Dec-97 Image Creation Method and Apparatus (IR10) PP0886 12-Dec-97 Image Creation Method and Apparatus (IR12) PP0871 12-Dec-97 A Device and Method (IR13) PP0876 12-Dec-97 An Image Processing Method and Apparatus (IR14) PP0877 12-Dec-97 A Device and Method (IR16) PP0878 12-Dec-97 A Device and Method (IR17) PP0879 12-Dec-97 A Device and Method (IR18) PP0883 12-Dec-97 A Device and Method (IR19) PP0880 12-Dec-97 A Device and Method (IR20) PP0881 12-Dec-97 A Device and Method (IR21)

DotCard Technologies

Further, the present application may include the utilization of a data distribution system such as that described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PP2370 16-Mar-98 Data Processing Method and Apparatus (Dot01) PP2371 16-Mar-98 Data Processing Method and Apparatus (Dot02)

Artcam Technologies

Further, the present application may include the utilization of camera and data processing techniques such as an Artcam type device as described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PO7991 15-Jul-97 Image Processing Method and Apparatus (ART01) PO8505 11-Aug-97 Image Processing Method and Apparatus (ART01a) PO7988 15-Jul-97 Image Processing Method and Apparatus (ART02) PO7993 15-Jul-97 Image Processing Method and Apparatus (ART03) PO8012 15-Jul-97 Image Processing Method and Apparatus (ART05) PO8017 15-Jul-97 Image Processing Method and Apparatus (ART06) PO8014 15-Jul-97 Media Device (ART07) PO8025 15-Jul-97 Image Processing Method and Apparatus (ART08) PO8032 15-Jul-97 Image Processing Method and Apparatus (ART09) PO7999 15-Jul-97 Image Processing Method and Apparatus (ART10) PO7998 15-Jul-97 Image Processing Method and Apparatus (ART11) PO8031 15-Jul-97 Image Processing Method and Apparatus (ART12) PO8030 15-Jul-97 Media Device (ART13) PO8498 11-Aug-97 Image Processing Method and Apparatus (ART14) PO7997 15-Jul-97 Media Device (ART15) PO7979 15-Jul-97 Media Device (ART16) PO8015 15-Jul-97 Media Device (ART17) PO7978 15-Jul-97 Media Device (ART18) PO7982 15-Jul-97 Data Processing Method and Apparatus (ART19) PO7989 15-Jul-97 Data Processing Method and Apparatus (ART20) PO8019 15-Jul-97 Media Processing Method and Apparatus (ART21) PO7980 15-Jul-97 Image Processing Method and Apparatus (ART22) PO7942 15-Jul-97 Image Processing Method and Apparatus (ART23) PO8018 15-Jul-97 Image Processing Method and Apparatus (ART24) PO7938 15-Jul-97 Image Processing Method and Apparatus (ART25) PO8016 15-Jul-97 Image Processing Method and Apparatus (ART26) PO8024 15-Jul-97 Image Processing Method and Apparatus (ART27) PO7940 15-Jul-97 Data Processing Method and Apparatus (ART28) PO7939 15-Jul-97 Data Processing Method and Apparatus (ART29) PO8501 11-Aug-97 Image Processing Method and Apparatus (ART30) PO8500 11-Aug-97 Image Processing Method and Apparatus (ART31) PO7987 15-Jul-97 Data Processing Method and Apparatus (ART32) PO8022 15-Jul-97 Image Processing Method and Apparatus (ART33) PO8497 11-Aug-97 Image Processing Method and Apparatus (ART30) PO8029 15-Jul-97 Sensor Creation Method and Apparatus (ART36) PO7985 15-Jul-97 Data Processing Method and Apparatus (ART37) PO8020 15-Jul-97 Data Processing Method and Apparatus (ART38) PO8023 15-Jul-97 Data Processing Method and Apparatus (ART39) PO9395 23-Sep-97 Data Processing Method and Apparatus (ART4) PO8021 15-Jul-97 Data Processing Method and Apparatus (ART40) PO8504 11-Aug-97 Image Processing Method and Apparatus (ART42) PO8000 15-Jul-97 Data Processing Method and Apparatus (ART43) PO7977 15-Jul-97 Data Processing Method and Apparatus (ART44) PO7934 15-Jul-97 Data Processing Method and Apparatus (ART45) PO7990 15-Jul-97 Data Processing Method and Apparatus (ART46) PO8499 11-Aug-97 Image Processing Method and Apparatus (ART47) PO8502 11-Aug-97 Image Processing Method and Apparatus (ART48) PO7981 15-Jul-97 Data Processing Method and Apparatus (ART50) PO7986 15-Jul-97 Data Processing Method and Apparatus (ART51) PO7983 15-Jul-97 Data Processing Method and Apparatus (ART52) PO8026 15-Jul-97 Image Processing Method and Apparatus (ART53) PO8027 15-Jul-97 Image Processing Method and Apparatus (ART54) PO8028 15-Jul-97 Image Processing Method and Apparatus (ART56) PO9394 23-Sep-97 Image Processing Method and Apparatus (ART57) PO9396 23-Sep-97 Data Processing Method and Apparatus (ART58) PO9397 23-Sep-97 Data Processing Method and Apparatus (ART59) PO9398 23-Sep-97 Data Processing Method and Apparatus (ART60) PO9399 23-Sep-97 Data Processing Method and Apparatus (ART61) PO9400 23-Sep-97 Data Processing Method and Apparatus (ART62) PO9401 23-Sep-97 Data Processing Method and Apparatus (ART63) PO9402 23-Sep-97 Data Processing Method and Apparatus (ART64) PO9403 23-Sep-97 Data Processing Method and Apparatus (ART65) PO9405 23-Sep-97 Data Processing Method and Apparatus (ART66) PP0959 16-Dec-97 A Data Processing Method and Apparatus (ART68) PP1397 19-Jan-98 A Media Device (ART69) 

1. A digital camera comprising: a printhead for printing images digitally captured by the camera; an ink supply for supplying ink to the printhead; and a casing surrounding and encasing the printhead and ink supply so that the ink supply is unable to be accessed without destruction of the casing.
 2. The camera of claim 1 wherein the casing comprises two shells, the shells being bonded together during one of a manufacturing process and a recycling process.
 3. The camera of claim 1 wherein the casing is recyclable.
 4. The camera of claim 1 wherein the ink supply is arranged to be refillable.
 5. The camera of claim 1 further comprising a print media supply for supplying print media to the printhead.
 6. The camera of claim 1 wherein the print media supply is releasably supported in the camera.
 7. The camera of claim 6 further comprising power supply means accommodated within the print media supply. 